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Zebrafish Provide the Keys to the Heart’s ‘Mini-Brain’
The heart’s “mini-brain” is independent and highly localized, according to researchers at the Karolinska Institutet in Stockholm, Sweden. The findings could lead to new research into arrhythmia, dementia, and Parkinson’s disease.
Although controlled by the brain, the heart has a separate, smaller intracardiac nervous system (IcNS) embedded within the superficial layers of the heart wall. Nicknamed the mini-brain by researchers decades ago, the IcNS was assumed to be a simple structure capable only of relaying simple information from the brain to the heart.
The neurons in the mini-brain, however, have been under-researched, said Konstantinos Ampatzis, principal researcher and assistant professor of neuroscience at the Karolinska Institutet. “Cardiologists know that neurons exist but never study them because their first concern is the cardiac muscle cells, or cardiomyocytes, that are responsible for the heartbeat,” he explained. “Neuroscientists understand and decode neurons but don’t know about neurons in the heart.”
Ampatzis’s team mapped the exact composition, organization, and function of neurons in the IcNS using zebrafish as an animal model. “The heart of the zebrafish is closer to that of humans than the mouse heart is,” he explained. “The heart rate of a zebrafish is exactly the same.”
Several techniques were used to characterize these neurons. Electrophysiology determined their function, and researchers at Columbia University in New York City helped identify their molecular signatures using single-cell RNA sequencing. Ampatzis and his team also analyzed neurotransmitters that the neurons release to communicate with each other. Researchers in Sweden and New York worked on this project in their spare time because they had no additional funding.
Ampatzis expected to see ganglions or relay neurons capable only of receiving or sending information. “But we found a very diverse set of neurons in a small network,” he said. Their findings included sympathetic, parasympathetic, and sensory neurons with apparent neurochemical and functional diversity. Most surprising was a subset of pacemaker neurons. “You cannot have a network that produces a rhythm without these neurons, and we didn’t expect exactly that, to be honest,” he said.
Pacemaker neurons are usually associated with so-called central pattern generator networks within the central nervous system. These independent, highly localized neuronal networks generate and control complex rhythmic behaviors such as respiration, mastication, urination, and ejaculation. “Most importantly, we found that this neuronal network works in an isolated heart, without brain information, and can change the rhythm of the heart and the regularity by itself,” said Ampatzis.
Further studies confirmed that neurons do not produce the rhythm, which is controlled by the cardiomyocytes. The neurons’ main function is to regulate the speed of the heartbeat. In other words, this smaller localized network acts as a kind of insurance system to safeguard the brain’s control of the heartbeat. “From an evolutionary perspective, I think that the system is like this because the heartbeat defines life,” Ampatzis added.
With the neurons of the heart mapped, medical researchers now have a toolbox of molecular markers, neurotransmitters, and other information on how such neurons function. These findings could become the basis of new research. It might be possible to investigate heart arrhythmia by modulating pacemaker neurons, Ampatzis suggested. “You could even repurpose or find specific drugs that can interfere with this local network of the heart,” he said, adding that this might be a less invasive option than is possible today.
Arrhythmia affects millions of people, said Oliver Guttmann, MD, a consultant cardiologist at The Wellington Hospital and honorary associate professor of cardiology at University College London, both in London, England. Beta-blockers remain the drug of choice for arrhythmia, but other options can be invasive. “We do ablations to try and burn or freeze certain areas of the heart to get rid of a rhythm because often this comes from hyperactive cells somewhere,” he said. Pacemakers and defibrillators are also needed to modulate dangerous rhythms. Innovation is focusing on making interventions far less invasive than they are today by creating smaller and smaller pacemakers, for example.
Moving from zebrafish to more complex mammalian systems will be the next big step, said David Paterson, DPhil, head of the Department of Physiology, Anatomy, and Genetics and honorary director of Burdon Sanderson Cardiac Science Centre at the University of Oxford in England. “If you can find the molecular road map of dysregulation, then that could be a potential target for a gene therapy or cell therapy or for neuromodulation therapy,” he explained. Interest in this field, which is sometimes called bioelectronic medicine, is mounting. “It’s like pharmaceutics, but there’s no drug. You’re tapping into the wiring of the nervous system,” he added.
More radical research pathways might look at ways to tackle neurodegenerative disorders from dementia to Parkinson’s disease. “If neurons die in the brain, then they die in the heart and can affect the rhythm of the heart,” said Ampatzis. But zebrafish neurons are now known to produce substances that induce a proliferation of stem cells in bones, skin, and even the nervous system. “We think those neurons of the heart could perhaps contribute to the regeneration of the heart,” he said.
Ampatzis, Guttmann, and Paterson reported having no relevant financial relationships.
A version of this article appeared on Medscape.com.
The heart’s “mini-brain” is independent and highly localized, according to researchers at the Karolinska Institutet in Stockholm, Sweden. The findings could lead to new research into arrhythmia, dementia, and Parkinson’s disease.
Although controlled by the brain, the heart has a separate, smaller intracardiac nervous system (IcNS) embedded within the superficial layers of the heart wall. Nicknamed the mini-brain by researchers decades ago, the IcNS was assumed to be a simple structure capable only of relaying simple information from the brain to the heart.
The neurons in the mini-brain, however, have been under-researched, said Konstantinos Ampatzis, principal researcher and assistant professor of neuroscience at the Karolinska Institutet. “Cardiologists know that neurons exist but never study them because their first concern is the cardiac muscle cells, or cardiomyocytes, that are responsible for the heartbeat,” he explained. “Neuroscientists understand and decode neurons but don’t know about neurons in the heart.”
Ampatzis’s team mapped the exact composition, organization, and function of neurons in the IcNS using zebrafish as an animal model. “The heart of the zebrafish is closer to that of humans than the mouse heart is,” he explained. “The heart rate of a zebrafish is exactly the same.”
Several techniques were used to characterize these neurons. Electrophysiology determined their function, and researchers at Columbia University in New York City helped identify their molecular signatures using single-cell RNA sequencing. Ampatzis and his team also analyzed neurotransmitters that the neurons release to communicate with each other. Researchers in Sweden and New York worked on this project in their spare time because they had no additional funding.
Ampatzis expected to see ganglions or relay neurons capable only of receiving or sending information. “But we found a very diverse set of neurons in a small network,” he said. Their findings included sympathetic, parasympathetic, and sensory neurons with apparent neurochemical and functional diversity. Most surprising was a subset of pacemaker neurons. “You cannot have a network that produces a rhythm without these neurons, and we didn’t expect exactly that, to be honest,” he said.
Pacemaker neurons are usually associated with so-called central pattern generator networks within the central nervous system. These independent, highly localized neuronal networks generate and control complex rhythmic behaviors such as respiration, mastication, urination, and ejaculation. “Most importantly, we found that this neuronal network works in an isolated heart, without brain information, and can change the rhythm of the heart and the regularity by itself,” said Ampatzis.
Further studies confirmed that neurons do not produce the rhythm, which is controlled by the cardiomyocytes. The neurons’ main function is to regulate the speed of the heartbeat. In other words, this smaller localized network acts as a kind of insurance system to safeguard the brain’s control of the heartbeat. “From an evolutionary perspective, I think that the system is like this because the heartbeat defines life,” Ampatzis added.
With the neurons of the heart mapped, medical researchers now have a toolbox of molecular markers, neurotransmitters, and other information on how such neurons function. These findings could become the basis of new research. It might be possible to investigate heart arrhythmia by modulating pacemaker neurons, Ampatzis suggested. “You could even repurpose or find specific drugs that can interfere with this local network of the heart,” he said, adding that this might be a less invasive option than is possible today.
Arrhythmia affects millions of people, said Oliver Guttmann, MD, a consultant cardiologist at The Wellington Hospital and honorary associate professor of cardiology at University College London, both in London, England. Beta-blockers remain the drug of choice for arrhythmia, but other options can be invasive. “We do ablations to try and burn or freeze certain areas of the heart to get rid of a rhythm because often this comes from hyperactive cells somewhere,” he said. Pacemakers and defibrillators are also needed to modulate dangerous rhythms. Innovation is focusing on making interventions far less invasive than they are today by creating smaller and smaller pacemakers, for example.
Moving from zebrafish to more complex mammalian systems will be the next big step, said David Paterson, DPhil, head of the Department of Physiology, Anatomy, and Genetics and honorary director of Burdon Sanderson Cardiac Science Centre at the University of Oxford in England. “If you can find the molecular road map of dysregulation, then that could be a potential target for a gene therapy or cell therapy or for neuromodulation therapy,” he explained. Interest in this field, which is sometimes called bioelectronic medicine, is mounting. “It’s like pharmaceutics, but there’s no drug. You’re tapping into the wiring of the nervous system,” he added.
More radical research pathways might look at ways to tackle neurodegenerative disorders from dementia to Parkinson’s disease. “If neurons die in the brain, then they die in the heart and can affect the rhythm of the heart,” said Ampatzis. But zebrafish neurons are now known to produce substances that induce a proliferation of stem cells in bones, skin, and even the nervous system. “We think those neurons of the heart could perhaps contribute to the regeneration of the heart,” he said.
Ampatzis, Guttmann, and Paterson reported having no relevant financial relationships.
A version of this article appeared on Medscape.com.
The heart’s “mini-brain” is independent and highly localized, according to researchers at the Karolinska Institutet in Stockholm, Sweden. The findings could lead to new research into arrhythmia, dementia, and Parkinson’s disease.
Although controlled by the brain, the heart has a separate, smaller intracardiac nervous system (IcNS) embedded within the superficial layers of the heart wall. Nicknamed the mini-brain by researchers decades ago, the IcNS was assumed to be a simple structure capable only of relaying simple information from the brain to the heart.
The neurons in the mini-brain, however, have been under-researched, said Konstantinos Ampatzis, principal researcher and assistant professor of neuroscience at the Karolinska Institutet. “Cardiologists know that neurons exist but never study them because their first concern is the cardiac muscle cells, or cardiomyocytes, that are responsible for the heartbeat,” he explained. “Neuroscientists understand and decode neurons but don’t know about neurons in the heart.”
Ampatzis’s team mapped the exact composition, organization, and function of neurons in the IcNS using zebrafish as an animal model. “The heart of the zebrafish is closer to that of humans than the mouse heart is,” he explained. “The heart rate of a zebrafish is exactly the same.”
Several techniques were used to characterize these neurons. Electrophysiology determined their function, and researchers at Columbia University in New York City helped identify their molecular signatures using single-cell RNA sequencing. Ampatzis and his team also analyzed neurotransmitters that the neurons release to communicate with each other. Researchers in Sweden and New York worked on this project in their spare time because they had no additional funding.
Ampatzis expected to see ganglions or relay neurons capable only of receiving or sending information. “But we found a very diverse set of neurons in a small network,” he said. Their findings included sympathetic, parasympathetic, and sensory neurons with apparent neurochemical and functional diversity. Most surprising was a subset of pacemaker neurons. “You cannot have a network that produces a rhythm without these neurons, and we didn’t expect exactly that, to be honest,” he said.
Pacemaker neurons are usually associated with so-called central pattern generator networks within the central nervous system. These independent, highly localized neuronal networks generate and control complex rhythmic behaviors such as respiration, mastication, urination, and ejaculation. “Most importantly, we found that this neuronal network works in an isolated heart, without brain information, and can change the rhythm of the heart and the regularity by itself,” said Ampatzis.
Further studies confirmed that neurons do not produce the rhythm, which is controlled by the cardiomyocytes. The neurons’ main function is to regulate the speed of the heartbeat. In other words, this smaller localized network acts as a kind of insurance system to safeguard the brain’s control of the heartbeat. “From an evolutionary perspective, I think that the system is like this because the heartbeat defines life,” Ampatzis added.
With the neurons of the heart mapped, medical researchers now have a toolbox of molecular markers, neurotransmitters, and other information on how such neurons function. These findings could become the basis of new research. It might be possible to investigate heart arrhythmia by modulating pacemaker neurons, Ampatzis suggested. “You could even repurpose or find specific drugs that can interfere with this local network of the heart,” he said, adding that this might be a less invasive option than is possible today.
Arrhythmia affects millions of people, said Oliver Guttmann, MD, a consultant cardiologist at The Wellington Hospital and honorary associate professor of cardiology at University College London, both in London, England. Beta-blockers remain the drug of choice for arrhythmia, but other options can be invasive. “We do ablations to try and burn or freeze certain areas of the heart to get rid of a rhythm because often this comes from hyperactive cells somewhere,” he said. Pacemakers and defibrillators are also needed to modulate dangerous rhythms. Innovation is focusing on making interventions far less invasive than they are today by creating smaller and smaller pacemakers, for example.
Moving from zebrafish to more complex mammalian systems will be the next big step, said David Paterson, DPhil, head of the Department of Physiology, Anatomy, and Genetics and honorary director of Burdon Sanderson Cardiac Science Centre at the University of Oxford in England. “If you can find the molecular road map of dysregulation, then that could be a potential target for a gene therapy or cell therapy or for neuromodulation therapy,” he explained. Interest in this field, which is sometimes called bioelectronic medicine, is mounting. “It’s like pharmaceutics, but there’s no drug. You’re tapping into the wiring of the nervous system,” he added.
More radical research pathways might look at ways to tackle neurodegenerative disorders from dementia to Parkinson’s disease. “If neurons die in the brain, then they die in the heart and can affect the rhythm of the heart,” said Ampatzis. But zebrafish neurons are now known to produce substances that induce a proliferation of stem cells in bones, skin, and even the nervous system. “We think those neurons of the heart could perhaps contribute to the regeneration of the heart,” he said.
Ampatzis, Guttmann, and Paterson reported having no relevant financial relationships.
A version of this article appeared on Medscape.com.
Clopidogrel Tops Aspirin Post-PCI, Even in High-Risk Cases
TOPLINE:
The beneficial effect of clopidogrel monotherapy over aspirin monotherapy in patients who underwent percutaneous coronary intervention (PCI) and remained event free for 6-18 months on dual antiplatelet therapy (DAPT) is consistent, regardless of bleeding risk or PCI complexity, according to a post hoc analysis of the HOST-EXAM trial.
METHODOLOGY:
- The HOST-EXAM Extended study conducted across 37 sites in South Korea included patients who underwent PCI with drug-eluting stents and remained free of clinical events for 6-18 months post-PCI, while receiving DAPT.
- This post hoc analysis of the HOST-EXAM Extended study compared the effectiveness of long-term daily clopidogrel (75 mg) with that of aspirin monotherapy (100 mg) after PCI, according to bleeding risk and procedural complexity in 3974 patients (mean age, 63 years; 75% men) who were followed for up to 5.9 years.
- High bleeding risk was reported in 866 patients, and 849 patients underwent complex PCI.
- Patients were classified into four distinct risk groups: No bleeding risk and noncomplex PCI, no bleeding risk and complex PCI, high bleeding risk and noncomplex PCI, and high bleeding risk and complex PCI.
- The co-primary endpoints were thrombotic composite events (cardiovascular death, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and definite/probable stent thrombosis) and any bleeding event.
TAKEAWAY:
- Thrombotic composite events (hazard ratio [HR], 2.15; P < .001) and any bleeding event (HR, 3.64; P < .001) were more frequent in patients with a high bleeding risk than in those without.
- However, there was no difference in the risk for thrombotic composite events or any bleeding event by PCI complexity.
- The long-term benefits of clopidogrel monotherapy over aspirin monotherapy were seen in all patients, regardless of bleeding risks (P for interaction = .38 for thrombotic composite events and P for interaction = .20 for any bleeding event) or PCI complexity (P for interaction = .12 for thrombotic composite events and P for interaction = .62 for any bleeding event).
- The greatest risk reduction in thrombotic composite events with clopidogrel monotherapy occurred in patients with a high bleeding risk who underwent complex PCI (HR, 0.46; P = .03).
IN PRACTICE:
“[In this study], no significant interaction was found between treatment arms and risk groups, denoting that the beneficial impact of clopidogrel monotherapy was consistent regardless of HBR [high bleeding risk] or PCI complexity,” the authors wrote.
SOURCE:
This study was led by Jeehoon Kang, MD, Seoul National University College of Medicine and Seoul National University Hospital, Seoul, Republic of Korea. It was published online on November 27, 2024, in JAMA Cardiology.
LIMITATIONS:
As this study is a post hoc analysis, the findings should be considered primarily hypothesis generating. This study was conducted exclusively in an East Asian population and may not be generalizable to other ethnic groups. The definitions of high bleeding risk and complex PCI used in this analysis were not prespecified in the study protocol of the HOST-EXAM trial. Certain criteria defining high bleeding risk were not analyzed as they fell under the exclusion criteria of the HOST-EXAM trial or were not recorded in the study case report form.
DISCLOSURES:
This study was supported by grants from the Patient-Centered Clinical Research Coordinating Center and Seoul National University Hospital. One author reported receiving grants and personal fees from various pharmaceutical companies outside the submitted work.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
The beneficial effect of clopidogrel monotherapy over aspirin monotherapy in patients who underwent percutaneous coronary intervention (PCI) and remained event free for 6-18 months on dual antiplatelet therapy (DAPT) is consistent, regardless of bleeding risk or PCI complexity, according to a post hoc analysis of the HOST-EXAM trial.
METHODOLOGY:
- The HOST-EXAM Extended study conducted across 37 sites in South Korea included patients who underwent PCI with drug-eluting stents and remained free of clinical events for 6-18 months post-PCI, while receiving DAPT.
- This post hoc analysis of the HOST-EXAM Extended study compared the effectiveness of long-term daily clopidogrel (75 mg) with that of aspirin monotherapy (100 mg) after PCI, according to bleeding risk and procedural complexity in 3974 patients (mean age, 63 years; 75% men) who were followed for up to 5.9 years.
- High bleeding risk was reported in 866 patients, and 849 patients underwent complex PCI.
- Patients were classified into four distinct risk groups: No bleeding risk and noncomplex PCI, no bleeding risk and complex PCI, high bleeding risk and noncomplex PCI, and high bleeding risk and complex PCI.
- The co-primary endpoints were thrombotic composite events (cardiovascular death, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and definite/probable stent thrombosis) and any bleeding event.
TAKEAWAY:
- Thrombotic composite events (hazard ratio [HR], 2.15; P < .001) and any bleeding event (HR, 3.64; P < .001) were more frequent in patients with a high bleeding risk than in those without.
- However, there was no difference in the risk for thrombotic composite events or any bleeding event by PCI complexity.
- The long-term benefits of clopidogrel monotherapy over aspirin monotherapy were seen in all patients, regardless of bleeding risks (P for interaction = .38 for thrombotic composite events and P for interaction = .20 for any bleeding event) or PCI complexity (P for interaction = .12 for thrombotic composite events and P for interaction = .62 for any bleeding event).
- The greatest risk reduction in thrombotic composite events with clopidogrel monotherapy occurred in patients with a high bleeding risk who underwent complex PCI (HR, 0.46; P = .03).
IN PRACTICE:
“[In this study], no significant interaction was found between treatment arms and risk groups, denoting that the beneficial impact of clopidogrel monotherapy was consistent regardless of HBR [high bleeding risk] or PCI complexity,” the authors wrote.
SOURCE:
This study was led by Jeehoon Kang, MD, Seoul National University College of Medicine and Seoul National University Hospital, Seoul, Republic of Korea. It was published online on November 27, 2024, in JAMA Cardiology.
LIMITATIONS:
As this study is a post hoc analysis, the findings should be considered primarily hypothesis generating. This study was conducted exclusively in an East Asian population and may not be generalizable to other ethnic groups. The definitions of high bleeding risk and complex PCI used in this analysis were not prespecified in the study protocol of the HOST-EXAM trial. Certain criteria defining high bleeding risk were not analyzed as they fell under the exclusion criteria of the HOST-EXAM trial or were not recorded in the study case report form.
DISCLOSURES:
This study was supported by grants from the Patient-Centered Clinical Research Coordinating Center and Seoul National University Hospital. One author reported receiving grants and personal fees from various pharmaceutical companies outside the submitted work.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
The beneficial effect of clopidogrel monotherapy over aspirin monotherapy in patients who underwent percutaneous coronary intervention (PCI) and remained event free for 6-18 months on dual antiplatelet therapy (DAPT) is consistent, regardless of bleeding risk or PCI complexity, according to a post hoc analysis of the HOST-EXAM trial.
METHODOLOGY:
- The HOST-EXAM Extended study conducted across 37 sites in South Korea included patients who underwent PCI with drug-eluting stents and remained free of clinical events for 6-18 months post-PCI, while receiving DAPT.
- This post hoc analysis of the HOST-EXAM Extended study compared the effectiveness of long-term daily clopidogrel (75 mg) with that of aspirin monotherapy (100 mg) after PCI, according to bleeding risk and procedural complexity in 3974 patients (mean age, 63 years; 75% men) who were followed for up to 5.9 years.
- High bleeding risk was reported in 866 patients, and 849 patients underwent complex PCI.
- Patients were classified into four distinct risk groups: No bleeding risk and noncomplex PCI, no bleeding risk and complex PCI, high bleeding risk and noncomplex PCI, and high bleeding risk and complex PCI.
- The co-primary endpoints were thrombotic composite events (cardiovascular death, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and definite/probable stent thrombosis) and any bleeding event.
TAKEAWAY:
- Thrombotic composite events (hazard ratio [HR], 2.15; P < .001) and any bleeding event (HR, 3.64; P < .001) were more frequent in patients with a high bleeding risk than in those without.
- However, there was no difference in the risk for thrombotic composite events or any bleeding event by PCI complexity.
- The long-term benefits of clopidogrel monotherapy over aspirin monotherapy were seen in all patients, regardless of bleeding risks (P for interaction = .38 for thrombotic composite events and P for interaction = .20 for any bleeding event) or PCI complexity (P for interaction = .12 for thrombotic composite events and P for interaction = .62 for any bleeding event).
- The greatest risk reduction in thrombotic composite events with clopidogrel monotherapy occurred in patients with a high bleeding risk who underwent complex PCI (HR, 0.46; P = .03).
IN PRACTICE:
“[In this study], no significant interaction was found between treatment arms and risk groups, denoting that the beneficial impact of clopidogrel monotherapy was consistent regardless of HBR [high bleeding risk] or PCI complexity,” the authors wrote.
SOURCE:
This study was led by Jeehoon Kang, MD, Seoul National University College of Medicine and Seoul National University Hospital, Seoul, Republic of Korea. It was published online on November 27, 2024, in JAMA Cardiology.
LIMITATIONS:
As this study is a post hoc analysis, the findings should be considered primarily hypothesis generating. This study was conducted exclusively in an East Asian population and may not be generalizable to other ethnic groups. The definitions of high bleeding risk and complex PCI used in this analysis were not prespecified in the study protocol of the HOST-EXAM trial. Certain criteria defining high bleeding risk were not analyzed as they fell under the exclusion criteria of the HOST-EXAM trial or were not recorded in the study case report form.
DISCLOSURES:
This study was supported by grants from the Patient-Centered Clinical Research Coordinating Center and Seoul National University Hospital. One author reported receiving grants and personal fees from various pharmaceutical companies outside the submitted work.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
Lung CT Can Detect Coronary Artery Disease, Predict Death
“The high prevalence of asymptomatic coronary artery disease (83%) was surprising, as was the prevalence of extensive CAC (30%),” principal investigator Gary Small, MBChB, PhD, a cardiologist at the University of Ottawa Heart Institute in Ontario, Canada, said in an interview.
“The size of effect was also surprising, as was the persistence of the effect even in the presence of elevated mortality risk from other causes,” he said. “Extensive coronary disease was associated with a twofold increase in risk for death or cardiovascular events over 4 years of follow-up,” even after adjustment for risk for death from cancer and other comorbidities such as chronic obstructive pulmonary disease.
“CAC as reported on chest CT exams is often ignored and not factored into clinical practice,” he noted. “The presence of CAC, however, provides a very real and very personal perspective on an individual’s cardiovascular risk. It is a true example of personalized medicine.”
The study was published online in The Canadian Medical Association Journal.
Potential Risk Reduction
In March 2017, Ontario Health launched a pilot low-dose CT lung cancer screening program for high-risk individuals between the ages of 55 and 74 years, Small explained. As CAC, a marker of coronary artery disease, is seen easily during such a scan, the researchers analyzed the lung CTs to determine the prevalence of coronary artery disease and whether CAC was associated with increased risk.
The team quantified CAC using an estimated Agatston score and identified the composite primary outcome of all-cause death and cardiovascular events using linked electronic medical record data from Ottawa Hospital up to December 2023. Among the 1486 people who underwent screening (mean age, 66 years; 52% men; 68% current smokers), CAC was detected in 1232 (82.9%). CAC was mild to moderate in 793 participants (53.4%) and extensive in 439 (29.5%). No CAC was detected in 254 (17.1%) participants.
At follow-up, 78 participants (5.2%) experienced the primary composite outcome, including 39 (8.9%) with extensive CAC, 32 (4.0%) with mild to moderate CAC, and 7 (2.8%) with no CAC.
A total of 49 deaths occurred, including 16 cardiovascular deaths and 19 cancer deaths, of which 10 were from lung cancer. Cardiovascular events included sudden cardiac death (eight participants), fatal stroke (six participants), and one each from heart failure and peripheral vascular disease.
On multivariable analysis, extensive CAC was associated with the composite primary outcome (adjusted hazard ratio [aHR], 2.13), all-cause mortality (aHR, 2.39), and cardiovascular events (aHR, 2.06).
Extensive CAC remained predictive of cardiovascular events even after adjustment for noncardiovascular death as a competing risk (HR, 2.05).
“Our data highlight to lung cancer screening professionals the prevalence of this silent risk factor and re-emphasize the importance of this finding [ie, CAC] as an opportunity for risk reduction,” Small said.
“In terms of next steps, the journey toward cardiovascular risk reduction begins with a clear report of CAC on the lung cancer screening record,” he noted. “Following this step, professionals involved in the lung cancer screening program might consider a local management pathway to ensure that this opportunity for health improvement is not lost or ignored. Preventive medicine of this type would typically involve primary care.”
Managing Other Findings
Commenting on the study, Anna Bader, MD, assistant professor of radiology and biomedical imaging at the Yale School of Medicine in New Haven, Connecticut, said that “low-dose CT for lung cancer screening offers valuable insights beyond nodule detection, with CAC being among the most significant incidental findings.”
However, she added, a “robust mechanism” to effectively manage other findings — such as thoracic aortic disease, low bone density, and abnormalities in the thyroid or upper abdominal organs — without overdiagnosis, is needed. A mechanism also is needed to notify cardiologists or primary care providers about severe CAC findings.
Challenges that need to be overcome before such mechanisms can be put in place, she said, “include ensuring standardized CAC reporting, avoiding overburdening healthcare providers, mitigating the risk of excessive downstream testing, and ensuring equitable access to follow-up care for underserved and rural communities.”
Providers involved in lung cancer screening “must be trained to recognize the importance of CAC findings and act upon them,” she added. “Awareness campaigns or continuing medical education modules could address this.”
Multidisciplinary lung cancer screening programs can help with patient education, she noted. “Clear communication about potential findings, including the significance of incidental CAC, should be prioritized and addressed proactively, ideally before the exam, to enhance patient understanding and engagement.”
Matthew Tomey, MD, assistant professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City, said that, “as a practicing cardiologist, I find it very helpful to look at my patients’ recent or past CT scans to look for vascular calcification. Whether or not a scan is specifically protocoled as a cardiac study, we can often appreciate vascular calcification when it is present. I would encourage every physician involved in helping their patients to prevent heart disease to take advantage of looking at any prior CT scans for evidence of vascular calcification.
“Systems of care to facilitate recognition of patients with incidentally discovered vascular calcification would be welcome and, on a large scale, could help prevent cardiovascular events,” he noted. “Such a system might involve facilitating referral to a prevention specialist. It could involve evidence-based guidance for referring physicians who ordered scans.”
Like Bader, he noted the importance of patient education, adding that it could be quite powerful. “We should be doing more to empower our patients to understand the findings of their imaging and to give them actionable, evidence-based guidance on how they can promote their own cardiovascular health,” he concluded.
No funding for the study was reported. Small reported receiving a research grant for amyloid research from Pfizer and honoraria from Pfizer and Alnylam (all paid to the institution, outside the submitted work). Bader and Tomey declared no relevant conflicts.
A version of this article first appeared on Medscape.com.
“The high prevalence of asymptomatic coronary artery disease (83%) was surprising, as was the prevalence of extensive CAC (30%),” principal investigator Gary Small, MBChB, PhD, a cardiologist at the University of Ottawa Heart Institute in Ontario, Canada, said in an interview.
“The size of effect was also surprising, as was the persistence of the effect even in the presence of elevated mortality risk from other causes,” he said. “Extensive coronary disease was associated with a twofold increase in risk for death or cardiovascular events over 4 years of follow-up,” even after adjustment for risk for death from cancer and other comorbidities such as chronic obstructive pulmonary disease.
“CAC as reported on chest CT exams is often ignored and not factored into clinical practice,” he noted. “The presence of CAC, however, provides a very real and very personal perspective on an individual’s cardiovascular risk. It is a true example of personalized medicine.”
The study was published online in The Canadian Medical Association Journal.
Potential Risk Reduction
In March 2017, Ontario Health launched a pilot low-dose CT lung cancer screening program for high-risk individuals between the ages of 55 and 74 years, Small explained. As CAC, a marker of coronary artery disease, is seen easily during such a scan, the researchers analyzed the lung CTs to determine the prevalence of coronary artery disease and whether CAC was associated with increased risk.
The team quantified CAC using an estimated Agatston score and identified the composite primary outcome of all-cause death and cardiovascular events using linked electronic medical record data from Ottawa Hospital up to December 2023. Among the 1486 people who underwent screening (mean age, 66 years; 52% men; 68% current smokers), CAC was detected in 1232 (82.9%). CAC was mild to moderate in 793 participants (53.4%) and extensive in 439 (29.5%). No CAC was detected in 254 (17.1%) participants.
At follow-up, 78 participants (5.2%) experienced the primary composite outcome, including 39 (8.9%) with extensive CAC, 32 (4.0%) with mild to moderate CAC, and 7 (2.8%) with no CAC.
A total of 49 deaths occurred, including 16 cardiovascular deaths and 19 cancer deaths, of which 10 were from lung cancer. Cardiovascular events included sudden cardiac death (eight participants), fatal stroke (six participants), and one each from heart failure and peripheral vascular disease.
On multivariable analysis, extensive CAC was associated with the composite primary outcome (adjusted hazard ratio [aHR], 2.13), all-cause mortality (aHR, 2.39), and cardiovascular events (aHR, 2.06).
Extensive CAC remained predictive of cardiovascular events even after adjustment for noncardiovascular death as a competing risk (HR, 2.05).
“Our data highlight to lung cancer screening professionals the prevalence of this silent risk factor and re-emphasize the importance of this finding [ie, CAC] as an opportunity for risk reduction,” Small said.
“In terms of next steps, the journey toward cardiovascular risk reduction begins with a clear report of CAC on the lung cancer screening record,” he noted. “Following this step, professionals involved in the lung cancer screening program might consider a local management pathway to ensure that this opportunity for health improvement is not lost or ignored. Preventive medicine of this type would typically involve primary care.”
Managing Other Findings
Commenting on the study, Anna Bader, MD, assistant professor of radiology and biomedical imaging at the Yale School of Medicine in New Haven, Connecticut, said that “low-dose CT for lung cancer screening offers valuable insights beyond nodule detection, with CAC being among the most significant incidental findings.”
However, she added, a “robust mechanism” to effectively manage other findings — such as thoracic aortic disease, low bone density, and abnormalities in the thyroid or upper abdominal organs — without overdiagnosis, is needed. A mechanism also is needed to notify cardiologists or primary care providers about severe CAC findings.
Challenges that need to be overcome before such mechanisms can be put in place, she said, “include ensuring standardized CAC reporting, avoiding overburdening healthcare providers, mitigating the risk of excessive downstream testing, and ensuring equitable access to follow-up care for underserved and rural communities.”
Providers involved in lung cancer screening “must be trained to recognize the importance of CAC findings and act upon them,” she added. “Awareness campaigns or continuing medical education modules could address this.”
Multidisciplinary lung cancer screening programs can help with patient education, she noted. “Clear communication about potential findings, including the significance of incidental CAC, should be prioritized and addressed proactively, ideally before the exam, to enhance patient understanding and engagement.”
Matthew Tomey, MD, assistant professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City, said that, “as a practicing cardiologist, I find it very helpful to look at my patients’ recent or past CT scans to look for vascular calcification. Whether or not a scan is specifically protocoled as a cardiac study, we can often appreciate vascular calcification when it is present. I would encourage every physician involved in helping their patients to prevent heart disease to take advantage of looking at any prior CT scans for evidence of vascular calcification.
“Systems of care to facilitate recognition of patients with incidentally discovered vascular calcification would be welcome and, on a large scale, could help prevent cardiovascular events,” he noted. “Such a system might involve facilitating referral to a prevention specialist. It could involve evidence-based guidance for referring physicians who ordered scans.”
Like Bader, he noted the importance of patient education, adding that it could be quite powerful. “We should be doing more to empower our patients to understand the findings of their imaging and to give them actionable, evidence-based guidance on how they can promote their own cardiovascular health,” he concluded.
No funding for the study was reported. Small reported receiving a research grant for amyloid research from Pfizer and honoraria from Pfizer and Alnylam (all paid to the institution, outside the submitted work). Bader and Tomey declared no relevant conflicts.
A version of this article first appeared on Medscape.com.
“The high prevalence of asymptomatic coronary artery disease (83%) was surprising, as was the prevalence of extensive CAC (30%),” principal investigator Gary Small, MBChB, PhD, a cardiologist at the University of Ottawa Heart Institute in Ontario, Canada, said in an interview.
“The size of effect was also surprising, as was the persistence of the effect even in the presence of elevated mortality risk from other causes,” he said. “Extensive coronary disease was associated with a twofold increase in risk for death or cardiovascular events over 4 years of follow-up,” even after adjustment for risk for death from cancer and other comorbidities such as chronic obstructive pulmonary disease.
“CAC as reported on chest CT exams is often ignored and not factored into clinical practice,” he noted. “The presence of CAC, however, provides a very real and very personal perspective on an individual’s cardiovascular risk. It is a true example of personalized medicine.”
The study was published online in The Canadian Medical Association Journal.
Potential Risk Reduction
In March 2017, Ontario Health launched a pilot low-dose CT lung cancer screening program for high-risk individuals between the ages of 55 and 74 years, Small explained. As CAC, a marker of coronary artery disease, is seen easily during such a scan, the researchers analyzed the lung CTs to determine the prevalence of coronary artery disease and whether CAC was associated with increased risk.
The team quantified CAC using an estimated Agatston score and identified the composite primary outcome of all-cause death and cardiovascular events using linked electronic medical record data from Ottawa Hospital up to December 2023. Among the 1486 people who underwent screening (mean age, 66 years; 52% men; 68% current smokers), CAC was detected in 1232 (82.9%). CAC was mild to moderate in 793 participants (53.4%) and extensive in 439 (29.5%). No CAC was detected in 254 (17.1%) participants.
At follow-up, 78 participants (5.2%) experienced the primary composite outcome, including 39 (8.9%) with extensive CAC, 32 (4.0%) with mild to moderate CAC, and 7 (2.8%) with no CAC.
A total of 49 deaths occurred, including 16 cardiovascular deaths and 19 cancer deaths, of which 10 were from lung cancer. Cardiovascular events included sudden cardiac death (eight participants), fatal stroke (six participants), and one each from heart failure and peripheral vascular disease.
On multivariable analysis, extensive CAC was associated with the composite primary outcome (adjusted hazard ratio [aHR], 2.13), all-cause mortality (aHR, 2.39), and cardiovascular events (aHR, 2.06).
Extensive CAC remained predictive of cardiovascular events even after adjustment for noncardiovascular death as a competing risk (HR, 2.05).
“Our data highlight to lung cancer screening professionals the prevalence of this silent risk factor and re-emphasize the importance of this finding [ie, CAC] as an opportunity for risk reduction,” Small said.
“In terms of next steps, the journey toward cardiovascular risk reduction begins with a clear report of CAC on the lung cancer screening record,” he noted. “Following this step, professionals involved in the lung cancer screening program might consider a local management pathway to ensure that this opportunity for health improvement is not lost or ignored. Preventive medicine of this type would typically involve primary care.”
Managing Other Findings
Commenting on the study, Anna Bader, MD, assistant professor of radiology and biomedical imaging at the Yale School of Medicine in New Haven, Connecticut, said that “low-dose CT for lung cancer screening offers valuable insights beyond nodule detection, with CAC being among the most significant incidental findings.”
However, she added, a “robust mechanism” to effectively manage other findings — such as thoracic aortic disease, low bone density, and abnormalities in the thyroid or upper abdominal organs — without overdiagnosis, is needed. A mechanism also is needed to notify cardiologists or primary care providers about severe CAC findings.
Challenges that need to be overcome before such mechanisms can be put in place, she said, “include ensuring standardized CAC reporting, avoiding overburdening healthcare providers, mitigating the risk of excessive downstream testing, and ensuring equitable access to follow-up care for underserved and rural communities.”
Providers involved in lung cancer screening “must be trained to recognize the importance of CAC findings and act upon them,” she added. “Awareness campaigns or continuing medical education modules could address this.”
Multidisciplinary lung cancer screening programs can help with patient education, she noted. “Clear communication about potential findings, including the significance of incidental CAC, should be prioritized and addressed proactively, ideally before the exam, to enhance patient understanding and engagement.”
Matthew Tomey, MD, assistant professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City, said that, “as a practicing cardiologist, I find it very helpful to look at my patients’ recent or past CT scans to look for vascular calcification. Whether or not a scan is specifically protocoled as a cardiac study, we can often appreciate vascular calcification when it is present. I would encourage every physician involved in helping their patients to prevent heart disease to take advantage of looking at any prior CT scans for evidence of vascular calcification.
“Systems of care to facilitate recognition of patients with incidentally discovered vascular calcification would be welcome and, on a large scale, could help prevent cardiovascular events,” he noted. “Such a system might involve facilitating referral to a prevention specialist. It could involve evidence-based guidance for referring physicians who ordered scans.”
Like Bader, he noted the importance of patient education, adding that it could be quite powerful. “We should be doing more to empower our patients to understand the findings of their imaging and to give them actionable, evidence-based guidance on how they can promote their own cardiovascular health,” he concluded.
No funding for the study was reported. Small reported receiving a research grant for amyloid research from Pfizer and honoraria from Pfizer and Alnylam (all paid to the institution, outside the submitted work). Bader and Tomey declared no relevant conflicts.
A version of this article first appeared on Medscape.com.
FROM THE CANADIAN MEDICAL ASSOCIATION JOURNAL
PRECISE-DAPT Score Predicts GI Bleeding Risk Among Post-PCI Patients
PHILADELPHIA — Gastrointestinal (GI) bleeding after percutaneous coronary intervention (PCI) among patients on dual antiplatelet therapy (DAPT) remains risky in terms of morbidity and mortality, but the Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy (PRECISE-DAPT) score could help predict that risk, according to a study presented at the American College of Gastroenterology (ACG) 2024 Annual Scientific Meeting.
In a predominantly Hispanic population in Texas, 2.5% of post-PCI patients on DAPT had GI bleeding in the first year.
“Our study established that the PRECISE-DAPT score possesses a moderate predictive accuracy not only for overall bleeding risk but also specifically for gastrointestinal bleeding,” said lead author Jesus Guzman, MD, a gastroenterology fellow at the Texas Tech University Health Sciences Center El Paso.
Current guidelines from the American College of Cardiology and American Heart Association recommend DAPT for 6-12 months post-PCI, with consideration for shorter durations in patients with lower ischemic risks but higher bleeding risks.
“Interestingly, some of these patients were on DAPT for more than 2 years, which goes beyond the guidelines,” he said. “In this patient population, this has to do with them being lost to follow-up and getting reestablished, and they kept refilling their prescriptions.”
Guzman and colleagues conducted a retrospective cohort study of patients receiving DAPT after PCI from 2014 to 2021. They looked for GI bleeding rates at 1 year and across the duration of the study period, as well as endoscopic indications, findings, concurrent antiplatelet therapy, and the primary cause of bleeding.
In addition, the research team evaluated the predictive value of the PRECISE-DAPT score, which categorizes patients based on low risk (≤ 17), moderate risk (18-24), and high risk (≥ 25) for bleeding. The score aims to optimize the balance between bleeding and ischemic risks, Guzman said, by incorporating five factors: Age, creatinine clearance, hemoglobin, white blood cell count, and history of spontaneous bleeding.
Among 1067 patients, 563 (57.9%) received clopidogrel and 409 (42%) received ticagrelor. The overall cohort was 66.6% men, 77.1% Hispanic, and had a mean age of 62 years.
The GI bleeding rate was 2.5% at 1-year post-PCI among 27 patients and 3.7% for the study duration among 39 patients, with a median follow-up of 2.2 years.
Among the 39 GI bleeds, 41% were lower GI bleeds, 28% were upper GI bleeds, 15% were small bowel bleeds, and 15% were undetermined. The most frequent etiology was colon cancer, accounting for 18% of bleeds, followed by 15% for gastric ulcers, 10% for diverticular bleeds, and 10% for hemorrhoidal bleeds.
In general, analyses indicated no significant differences in GI bleeding between patients on clopidogrel (21.2%) and those on ticagrelor (19.2%).
However, the odds of GI bleeding were significantly higher in patients with high-risk PRECISE-DAPT scores (odds ratio [OR], 2.5) and moderate-risk scores (OR, 2.8) than in those with low-risk scores. The majority of patients without GI bleeding had scores < 17, whereas the majority of patients with GI bleeding had scores > 24. An optimal threshold for the PRECISE-DAPT score was identified as ≥ 19.
“When patients on DAPT present with GI bleeding, it can be a clinical conundrum for gastroenterologists and cardiologists, especially when it can be a life-or-death event, and stopping DAPT can increase risk of thrombosis,” said Jeff Taclob, MD, a hepatology fellow at The University of Tennessee Health Science Center in Memphis. Taclob, who wasn’t involved with the study, attended the conference session.
“In this population in El Paso, in particular, many patients don’t have adequate healthcare, may be lost to follow-up, and get their prescriptions filled elsewhere, such as Juárez, Mexico,” he said. “Then they come in with this life-threatening bleed, so we need to focus more on their risks.”
Paying attention to specific patient populations, cultures, and values remains important for patient communication and clinical decision-making, Taclob noted.
“In this population of older men, there’s often a macho persona where they don’t want to seek help,” he said. “DAPT criteria could differ in other populations, but here, the PRECISE-DAPT score appeared to help.”
The study was awarded the ACG Outstanding Research Award in the GI Bleeding Category (Trainee). Guzman and Taclob reported no relevant disclosures.
A version of this article first appeared on Medscape.com.
PHILADELPHIA — Gastrointestinal (GI) bleeding after percutaneous coronary intervention (PCI) among patients on dual antiplatelet therapy (DAPT) remains risky in terms of morbidity and mortality, but the Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy (PRECISE-DAPT) score could help predict that risk, according to a study presented at the American College of Gastroenterology (ACG) 2024 Annual Scientific Meeting.
In a predominantly Hispanic population in Texas, 2.5% of post-PCI patients on DAPT had GI bleeding in the first year.
“Our study established that the PRECISE-DAPT score possesses a moderate predictive accuracy not only for overall bleeding risk but also specifically for gastrointestinal bleeding,” said lead author Jesus Guzman, MD, a gastroenterology fellow at the Texas Tech University Health Sciences Center El Paso.
Current guidelines from the American College of Cardiology and American Heart Association recommend DAPT for 6-12 months post-PCI, with consideration for shorter durations in patients with lower ischemic risks but higher bleeding risks.
“Interestingly, some of these patients were on DAPT for more than 2 years, which goes beyond the guidelines,” he said. “In this patient population, this has to do with them being lost to follow-up and getting reestablished, and they kept refilling their prescriptions.”
Guzman and colleagues conducted a retrospective cohort study of patients receiving DAPT after PCI from 2014 to 2021. They looked for GI bleeding rates at 1 year and across the duration of the study period, as well as endoscopic indications, findings, concurrent antiplatelet therapy, and the primary cause of bleeding.
In addition, the research team evaluated the predictive value of the PRECISE-DAPT score, which categorizes patients based on low risk (≤ 17), moderate risk (18-24), and high risk (≥ 25) for bleeding. The score aims to optimize the balance between bleeding and ischemic risks, Guzman said, by incorporating five factors: Age, creatinine clearance, hemoglobin, white blood cell count, and history of spontaneous bleeding.
Among 1067 patients, 563 (57.9%) received clopidogrel and 409 (42%) received ticagrelor. The overall cohort was 66.6% men, 77.1% Hispanic, and had a mean age of 62 years.
The GI bleeding rate was 2.5% at 1-year post-PCI among 27 patients and 3.7% for the study duration among 39 patients, with a median follow-up of 2.2 years.
Among the 39 GI bleeds, 41% were lower GI bleeds, 28% were upper GI bleeds, 15% were small bowel bleeds, and 15% were undetermined. The most frequent etiology was colon cancer, accounting for 18% of bleeds, followed by 15% for gastric ulcers, 10% for diverticular bleeds, and 10% for hemorrhoidal bleeds.
In general, analyses indicated no significant differences in GI bleeding between patients on clopidogrel (21.2%) and those on ticagrelor (19.2%).
However, the odds of GI bleeding were significantly higher in patients with high-risk PRECISE-DAPT scores (odds ratio [OR], 2.5) and moderate-risk scores (OR, 2.8) than in those with low-risk scores. The majority of patients without GI bleeding had scores < 17, whereas the majority of patients with GI bleeding had scores > 24. An optimal threshold for the PRECISE-DAPT score was identified as ≥ 19.
“When patients on DAPT present with GI bleeding, it can be a clinical conundrum for gastroenterologists and cardiologists, especially when it can be a life-or-death event, and stopping DAPT can increase risk of thrombosis,” said Jeff Taclob, MD, a hepatology fellow at The University of Tennessee Health Science Center in Memphis. Taclob, who wasn’t involved with the study, attended the conference session.
“In this population in El Paso, in particular, many patients don’t have adequate healthcare, may be lost to follow-up, and get their prescriptions filled elsewhere, such as Juárez, Mexico,” he said. “Then they come in with this life-threatening bleed, so we need to focus more on their risks.”
Paying attention to specific patient populations, cultures, and values remains important for patient communication and clinical decision-making, Taclob noted.
“In this population of older men, there’s often a macho persona where they don’t want to seek help,” he said. “DAPT criteria could differ in other populations, but here, the PRECISE-DAPT score appeared to help.”
The study was awarded the ACG Outstanding Research Award in the GI Bleeding Category (Trainee). Guzman and Taclob reported no relevant disclosures.
A version of this article first appeared on Medscape.com.
PHILADELPHIA — Gastrointestinal (GI) bleeding after percutaneous coronary intervention (PCI) among patients on dual antiplatelet therapy (DAPT) remains risky in terms of morbidity and mortality, but the Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy (PRECISE-DAPT) score could help predict that risk, according to a study presented at the American College of Gastroenterology (ACG) 2024 Annual Scientific Meeting.
In a predominantly Hispanic population in Texas, 2.5% of post-PCI patients on DAPT had GI bleeding in the first year.
“Our study established that the PRECISE-DAPT score possesses a moderate predictive accuracy not only for overall bleeding risk but also specifically for gastrointestinal bleeding,” said lead author Jesus Guzman, MD, a gastroenterology fellow at the Texas Tech University Health Sciences Center El Paso.
Current guidelines from the American College of Cardiology and American Heart Association recommend DAPT for 6-12 months post-PCI, with consideration for shorter durations in patients with lower ischemic risks but higher bleeding risks.
“Interestingly, some of these patients were on DAPT for more than 2 years, which goes beyond the guidelines,” he said. “In this patient population, this has to do with them being lost to follow-up and getting reestablished, and they kept refilling their prescriptions.”
Guzman and colleagues conducted a retrospective cohort study of patients receiving DAPT after PCI from 2014 to 2021. They looked for GI bleeding rates at 1 year and across the duration of the study period, as well as endoscopic indications, findings, concurrent antiplatelet therapy, and the primary cause of bleeding.
In addition, the research team evaluated the predictive value of the PRECISE-DAPT score, which categorizes patients based on low risk (≤ 17), moderate risk (18-24), and high risk (≥ 25) for bleeding. The score aims to optimize the balance between bleeding and ischemic risks, Guzman said, by incorporating five factors: Age, creatinine clearance, hemoglobin, white blood cell count, and history of spontaneous bleeding.
Among 1067 patients, 563 (57.9%) received clopidogrel and 409 (42%) received ticagrelor. The overall cohort was 66.6% men, 77.1% Hispanic, and had a mean age of 62 years.
The GI bleeding rate was 2.5% at 1-year post-PCI among 27 patients and 3.7% for the study duration among 39 patients, with a median follow-up of 2.2 years.
Among the 39 GI bleeds, 41% were lower GI bleeds, 28% were upper GI bleeds, 15% were small bowel bleeds, and 15% were undetermined. The most frequent etiology was colon cancer, accounting for 18% of bleeds, followed by 15% for gastric ulcers, 10% for diverticular bleeds, and 10% for hemorrhoidal bleeds.
In general, analyses indicated no significant differences in GI bleeding between patients on clopidogrel (21.2%) and those on ticagrelor (19.2%).
However, the odds of GI bleeding were significantly higher in patients with high-risk PRECISE-DAPT scores (odds ratio [OR], 2.5) and moderate-risk scores (OR, 2.8) than in those with low-risk scores. The majority of patients without GI bleeding had scores < 17, whereas the majority of patients with GI bleeding had scores > 24. An optimal threshold for the PRECISE-DAPT score was identified as ≥ 19.
“When patients on DAPT present with GI bleeding, it can be a clinical conundrum for gastroenterologists and cardiologists, especially when it can be a life-or-death event, and stopping DAPT can increase risk of thrombosis,” said Jeff Taclob, MD, a hepatology fellow at The University of Tennessee Health Science Center in Memphis. Taclob, who wasn’t involved with the study, attended the conference session.
“In this population in El Paso, in particular, many patients don’t have adequate healthcare, may be lost to follow-up, and get their prescriptions filled elsewhere, such as Juárez, Mexico,” he said. “Then they come in with this life-threatening bleed, so we need to focus more on their risks.”
Paying attention to specific patient populations, cultures, and values remains important for patient communication and clinical decision-making, Taclob noted.
“In this population of older men, there’s often a macho persona where they don’t want to seek help,” he said. “DAPT criteria could differ in other populations, but here, the PRECISE-DAPT score appeared to help.”
The study was awarded the ACG Outstanding Research Award in the GI Bleeding Category (Trainee). Guzman and Taclob reported no relevant disclosures.
A version of this article first appeared on Medscape.com.
FROM ACG 2024
Maternal Serum Folate Levels During Pregnancy Linked to Congenital Heart Disease Risk
TOPLINE:
Maternal serum folate levels during early to midpregnancy show a U-shaped association with congenital heart disease (CHD) risk in offspring. Both low and high folate levels are linked to an increased risk, with vitamin B12 deficiency and elevated homocysteine levels further exacerbating this risk.
METHODOLOGY:
- Researchers conducted a case-control study with 129 participants with CHD and 516 matched control participants from Guangdong Provincial People’s Hospital in China between 2015 and 2018.
- Maternal serum levels of folate, vitamin B12, and homocysteine were measured at around 16 weeks of gestation using a chemiluminescence microparticle immunoassay.
- CHD was confirmed using echocardiography, and the participants were matched by maternal age at a ratio of 1:4.
- Covariates included periconceptional folic acid supplementation, maternal education, occupation, parity, abortion history, pregnancy complications, and genetic polymorphisms related to folate metabolism.
- Conditional logistic regression was used to assess the associations, with adjustments for various covariates and sensitivity analyses excluding participants with missing genetic data.
TAKEAWAY:
- A U-shaped association was found between maternal serum folate levels and CHD risk in offspring, with both low and high levels linked to increased risk (P < .001).
- Low maternal folate levels were associated with an adjusted odds ratio (aOR) of 3.09 (95% CI, 1.88-5.08) for CHD risk, whereas high levels had an aOR of 1.81 (95% CI, 1.07-3.06).
- Using World Health Organization criteria, folate deficiency (< 5.9 ng/mL) had an aOR of 18.97 (95% CI, 3.87-93.11) and elevated levels (> 20 ng/mL) had an aOR of 5.71 (95% CI, 2.72-11.98) for CHD risk.
- Vitamin B12 deficiency and elevated homocysteine levels further increased the risk associated with both low and high maternal folate levels.
IN PRACTICE:
“Insufficient folate and vitamin B12 can lead to increased homocysteine levels, which is harmful to the cardiovascular system. Thus, homocysteine might act as a central mediator in the relationships between deficiencies in folate and vitamin B12 and the risk of CHD. Additionally, the role of folate extends beyond homocysteine mediation, contributing independently to placental implantation and vascular remodeling, irrespective of vitamin B12 and homocysteine levels,” the authors wrote.
SOURCE:
The study was led by Yanji Qu, PhD, and Jie Li, PhD, Global Health Research Center, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China. It was published online in JAMA Network Open.
LIMITATIONS:
The study’s limitations included the measurement of maternal serum folate levels at a single time point, which may not reflect preconception and early postconception periods. The study’s findings may not be generalizable to other populations as participants were recruited from a single cardiac referral center in Southern China. Additionally, the lack of dietary intake data limited the ability to account for related biases. The sample size, while relatively large for CHD research, may lack sufficient power for stratified analyses.
DISCLOSURES:
One coauthor reported receiving personal fees from Guangdong Cardiovascular Institute outside the submitted work. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
Maternal serum folate levels during early to midpregnancy show a U-shaped association with congenital heart disease (CHD) risk in offspring. Both low and high folate levels are linked to an increased risk, with vitamin B12 deficiency and elevated homocysteine levels further exacerbating this risk.
METHODOLOGY:
- Researchers conducted a case-control study with 129 participants with CHD and 516 matched control participants from Guangdong Provincial People’s Hospital in China between 2015 and 2018.
- Maternal serum levels of folate, vitamin B12, and homocysteine were measured at around 16 weeks of gestation using a chemiluminescence microparticle immunoassay.
- CHD was confirmed using echocardiography, and the participants were matched by maternal age at a ratio of 1:4.
- Covariates included periconceptional folic acid supplementation, maternal education, occupation, parity, abortion history, pregnancy complications, and genetic polymorphisms related to folate metabolism.
- Conditional logistic regression was used to assess the associations, with adjustments for various covariates and sensitivity analyses excluding participants with missing genetic data.
TAKEAWAY:
- A U-shaped association was found between maternal serum folate levels and CHD risk in offspring, with both low and high levels linked to increased risk (P < .001).
- Low maternal folate levels were associated with an adjusted odds ratio (aOR) of 3.09 (95% CI, 1.88-5.08) for CHD risk, whereas high levels had an aOR of 1.81 (95% CI, 1.07-3.06).
- Using World Health Organization criteria, folate deficiency (< 5.9 ng/mL) had an aOR of 18.97 (95% CI, 3.87-93.11) and elevated levels (> 20 ng/mL) had an aOR of 5.71 (95% CI, 2.72-11.98) for CHD risk.
- Vitamin B12 deficiency and elevated homocysteine levels further increased the risk associated with both low and high maternal folate levels.
IN PRACTICE:
“Insufficient folate and vitamin B12 can lead to increased homocysteine levels, which is harmful to the cardiovascular system. Thus, homocysteine might act as a central mediator in the relationships between deficiencies in folate and vitamin B12 and the risk of CHD. Additionally, the role of folate extends beyond homocysteine mediation, contributing independently to placental implantation and vascular remodeling, irrespective of vitamin B12 and homocysteine levels,” the authors wrote.
SOURCE:
The study was led by Yanji Qu, PhD, and Jie Li, PhD, Global Health Research Center, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China. It was published online in JAMA Network Open.
LIMITATIONS:
The study’s limitations included the measurement of maternal serum folate levels at a single time point, which may not reflect preconception and early postconception periods. The study’s findings may not be generalizable to other populations as participants were recruited from a single cardiac referral center in Southern China. Additionally, the lack of dietary intake data limited the ability to account for related biases. The sample size, while relatively large for CHD research, may lack sufficient power for stratified analyses.
DISCLOSURES:
One coauthor reported receiving personal fees from Guangdong Cardiovascular Institute outside the submitted work. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
Maternal serum folate levels during early to midpregnancy show a U-shaped association with congenital heart disease (CHD) risk in offspring. Both low and high folate levels are linked to an increased risk, with vitamin B12 deficiency and elevated homocysteine levels further exacerbating this risk.
METHODOLOGY:
- Researchers conducted a case-control study with 129 participants with CHD and 516 matched control participants from Guangdong Provincial People’s Hospital in China between 2015 and 2018.
- Maternal serum levels of folate, vitamin B12, and homocysteine were measured at around 16 weeks of gestation using a chemiluminescence microparticle immunoassay.
- CHD was confirmed using echocardiography, and the participants were matched by maternal age at a ratio of 1:4.
- Covariates included periconceptional folic acid supplementation, maternal education, occupation, parity, abortion history, pregnancy complications, and genetic polymorphisms related to folate metabolism.
- Conditional logistic regression was used to assess the associations, with adjustments for various covariates and sensitivity analyses excluding participants with missing genetic data.
TAKEAWAY:
- A U-shaped association was found between maternal serum folate levels and CHD risk in offspring, with both low and high levels linked to increased risk (P < .001).
- Low maternal folate levels were associated with an adjusted odds ratio (aOR) of 3.09 (95% CI, 1.88-5.08) for CHD risk, whereas high levels had an aOR of 1.81 (95% CI, 1.07-3.06).
- Using World Health Organization criteria, folate deficiency (< 5.9 ng/mL) had an aOR of 18.97 (95% CI, 3.87-93.11) and elevated levels (> 20 ng/mL) had an aOR of 5.71 (95% CI, 2.72-11.98) for CHD risk.
- Vitamin B12 deficiency and elevated homocysteine levels further increased the risk associated with both low and high maternal folate levels.
IN PRACTICE:
“Insufficient folate and vitamin B12 can lead to increased homocysteine levels, which is harmful to the cardiovascular system. Thus, homocysteine might act as a central mediator in the relationships between deficiencies in folate and vitamin B12 and the risk of CHD. Additionally, the role of folate extends beyond homocysteine mediation, contributing independently to placental implantation and vascular remodeling, irrespective of vitamin B12 and homocysteine levels,” the authors wrote.
SOURCE:
The study was led by Yanji Qu, PhD, and Jie Li, PhD, Global Health Research Center, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China. It was published online in JAMA Network Open.
LIMITATIONS:
The study’s limitations included the measurement of maternal serum folate levels at a single time point, which may not reflect preconception and early postconception periods. The study’s findings may not be generalizable to other populations as participants were recruited from a single cardiac referral center in Southern China. Additionally, the lack of dietary intake data limited the ability to account for related biases. The sample size, while relatively large for CHD research, may lack sufficient power for stratified analyses.
DISCLOSURES:
One coauthor reported receiving personal fees from Guangdong Cardiovascular Institute outside the submitted work. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
‘Shed the Lead’ and the Injuries. Should Cath Labs Go Lead-Free?
“I’d probably be a quadriplegic,” Dean J. Kereiakes, MD, an interventional cardiologist, said when asked what would have happened if two top neurosurgeons at his hospital hadn’t rushed him to the operating room (OR) for a cervical decompression in February this year.
Dr. Kereiakes had orthopedic problems for years due to the heavy lead aprons he wore in the cath lab. He regularly dosed himself with steroids for disc pain so he could stand up straight and continue to do procedures. “Several times a year I’d go on a tapering dose of prednisone of about 10 days to 2 weeks, and this would take care of it.”
But then his luck ran out. “I’m told in retrospect that my gait — the way I walked — was different, and I was also having some myoclonic jerking in my legs when I was going to sleep. I thought it was peculiar, but I didn’t really tie it together that this was an upper tract injury response.”
At a restaurant with his wife, he found himself unable to sign the check. “I couldn’t write my name.” By the next morning, “I had a floppy right foot, and as I turned around to put my scrubs on, everything fell apart. My arms began to not function and my legs — I couldn’t walk.”
Admitted to The Christ Hospital Heart & Vascular Center in Cincinnati — the very hospital he works in — Dr. Kereiakes had CT and MRI scans and consulted with neurosurgeons he counts as friends. He was given extremely high doses of intravenous steroids. “But instead of getting better, the pain came back, and I started posturing — when you posture, it looks like a praying mantis, your arms are flexed up, your wrists are flexed, and your fingers are spasmed together.” His wife and the nurses couldn’t pull his fingers open, “so they rolled me back, and the posturing started to go away.”
This prompted the neurosurgeons to bring him to the OR “by 6 a.m., and they are ‘unzipping me in the back’ to basically get my spinal cord off my spine. I had cord compression at C2-3 and C 6-7.”
Postop, Dr. Kereiakes couldn’t move his right leg and couldn’t close any of his fingers. “You lose control of things like bladder and bowel function — you have a catheter in — and you say to yourself, ‘How am I going to live like this?.’ ”
The quick-thinking of his neurosurgeons prevented permanent paralysis, and after a long 6-month recovery, Dr. Kereiakes is back in the cath lab, performing procedures. But crucially, he will no longer have to wear a lead apron.
Ending Careers Early. A Catalyst for Change
Typically, interventional cardiologists, interventional radiologists, electrophysiologists, and others working in labs where they are exposed to ionizing radiation wear lead aprons and garments, such as thyroid collars, leaded caps, and glasses, to protect them during procedures.
Long-term occupational exposure to radiation is linked to cataracts; brain tumors; cancers, including leukemia, multiple myelomas, lymphomas, and thyroid cancers; and left-sided breast cancers in women because the aprons don’t always cover the left side of the chest adequately.
Individual states set the standards in terms of the thickness of the lead required, varying from 0.25- to 0.5-mm–lead-equivalent aprons, which reduce exposure by 85%-95%. Radiation safety officers monitor the badges that staff wear to record their radiation exposure and will warn them when their levels are too high.
But — as Dr. Kereiakes freely admits — ambitious interventionalists don’t always take much notice. “They would come and say, ‘Hey your badge is really high,’ and so I would just put it in a drawer and carry on,” he said. “When you are younger, you feel immortal.”
James B. Hermiller Jr., MD, president of the Society for Cardiovascular Angiography & Interventions (SCAI), agrees: “The feeling is that, with lead, you are indestructible, and no one wants to show any weakness.”
Another occupational hazard related to those protective lead aprons was also being ignored, that of orthopedic injury. In surveys done by SCAI, around half of interventional cardiology respondents report cervical, lumbar, hip, knee, or ankle joint injuries.
While Dr. Kereiakes recognizes likely bias — with those afflicted more likely to complete these surveys — he believes that the problem is huge and “is ending careers early.”
“It’s interesting that radiation is at the forefront of protection and occupational safety, but you are much more likely to be taken out of work because of orthopedic injury,” explained Dr. Hermiller, director of Structural Heart Program at Ascension St. Vincent Heart Center in Indianapolis.
His own story “is not as compelling as Dean’s, but 17 years ago, I ruptured a disk in my lower spine and had emergent surgery and I now need a neck surgery.”
Dr. Hermiller’s hospital, too, has purchased multiple radiation protection systems. “If you want to do this job for 30 years, you have to protect yourself early and at all times,” he said.
His focus as SCAI president is to help get these protection systems in place at more hospitals.
But significant challenges remain, not least the cost, which can be $150,000-$200,000 per lab. He estimates that fewer than 10% US hospitals with cath and other labs using radiation have installed such systems.
Most systems are not US Food and Drug Administration (FDA) approved because they are not attached to equipment in the cath lab, something that Nadia Sutton, MD, MPH, chair of the SCAI Women in Innovations committee, said many physicians are not aware of. “The companies [marketing the systems] are telling us that we can ‘shed our lead,’ ” she said. “It could be safe, but we are using the data provided by the companies.”
How Do the Lead-Free Systems Work?
Currently, there are three main radiation protection systems available. The Protego Radiation Protection System (Image Diagnostics), the EggNest Protect (Egg Medical), and the Rampart (Rampart ic).
According to Dr. Kereiakes, they differ somewhat in whether they allow immediate access to the patient or whether you can see and interact with them. He explained that in high-risk procedures, easy access is desirable. “If you get a perforation or tamponade and the patient suddenly goes ‘out,’ you need to be able to get to them quickly, and you can’t be spending a lot of time taking the shielding down.”
Dr. Kereiakes was recovering in the hospital when his colleagues plumped for the EggNest system. He thinks they chose it because it offers visibility and access to the patient and “takes 4-5 minutes, maximum, to set up.” So far, he agrees with the choice but wants to “give it a real, volume-driven try.”
If they are satisfied with the system, the hospital will order six more by the end of the year, he said. A significant financial undertaking, he acknowledged.
Dr. Hermiller cited data for the Rampart system showing a 95% reduction in radiation without any lead. For an average 1-GRAY radiation exposure case, “if you wear lead, you reach the maximum dose of radiation around 850 cases in a year. If you do it with one of these protection systems, in this case Rampart, you can do 14,500 cases in a year. Not that anyone would do that [many].”
The Protego system has very similar data, he noted. The systems protect the operator and whoever is scrubbing in at the table, so those on the other side of the protector still need to wear lead, Dr. Hermiller stressed.
Data for the EggNest Protect are available but are as yet unpublished.
Dr. Hermiller acknowledged that there is still a long way to go in getting hospitals to spend the money on these systems, but he thinks cath lab operators will drive the change.
“At our SCAI meeting this year, the biggest attendance was at a session about a lead-free cath lab environment.”
Regulation at the State Level
Despite the excitement among the profession, Dr. Sutton — director of Interventional Cardiology Research in the Division of Cardiovascular Medicine at Vanderbilt University Medical Center, Nashville, Tennessee — still has concerns about the lack of FDA regulation.
There is one newer system, called the Radiaction shield system, that attaches to the existing equipment so that is regulated by the FDA as a class II device, she noted. “But it is my understanding that the Protego, Rampart, and EggNest are Class I Exempt. That is the same category as Band-Aid.”
James Beabout, MBA, chief marketing officer, Egg Medical, confirmed that the EggNest “is classified as a Class I device which does not require FDA approval. That leaves regulation to each state regarding the requirements for protective aprons.” And Mark Hansen, vice president business development, of Image Diagnostics — the manufacturer of the Protego Radiation Protection System — confirmed that “the real governance is at the state level.”
The company petitions the state regulator for an exemption letter to the wearing of lead aprons. “In some cases, the state will come to the site directly and validate the systems integrity and to confirm their decision. Once the exemption is granted, the state sends a document, and it’s the responsibility of the sites’ Radiation Safety Officer (RSO) to change the labs safety process and rules,” Mr. Hansen explained.
“What really makes this work is a real-time dosimetry from Fluke Medical. Staff wear one to two badges that instantly detects exposure,” Mr. Hansen stressed.
Similarly, said Mr. Beabout, Egg Medical has data from over 1000 real-world cases collected using real-time dosimetry (RaySafe i3 system) which demonstrate that it is possible to get some people in the room out of protective aprons, where allowed. They recommend real-time dosimetry anytime people are removing their aprons, “since the patient BMI, x-ray system type/age, and complexity of the case all have a significant effect on the radiation dose in each case.” Their goal is for exposure to be zero or as close to zero as possible, “otherwise we recommend use of protective aprons. With the EggNest, operators can use much lighter aprons (0.125 mm sold by Burlington Medical) than what has traditionally been used, so that is also an option,” he said.
Dr. Hermiller said the SCAI plan is to produce several statements on going lead-free, with all other interested professional societies — such as those representing interventional radiologists and vascular surgeons, as well as all the major cardiology societies.
“We want to make an intellectual foundation for this,” Dr. Hermiller explained. Guidelines “are in the making,” he said, with the expectation that they will be ready by the end of this year or early next year.
SCAI will also work with the 50 US states to facilitate lead-free labs, “as each one has a different way to be approved to go without lead,” he noted.
“This is not going to go away, it’s going to build in force, through the societies,” said Dr. Kereiakes. “It’s a matter of workplace safety.” He doesn’t think that the federal Occupational Health and Safety Administration does much to protect doctors, nurses, and technicians in the cath and other labs.
Dr. Hermiller agreed: “I always say that if we were a GM car plant, they would shut us down.”
Dr. Hermiller also stressed the expense of having doctors and other staff off work with occupation-related injuries. He has already observed that “it’s much easier to recruit cath lab staff to a place where they don’t have to wear lead.”
He anticipates that the next generation of physicians “are going to demand places where they don’t have to wear lead.” He is also hopeful that it will result in more women choosing interventional cardiology: “Women are safe in the cath lab with current lead systems, but if we could move to this, there would be even more women participating.”
Pregnancy Safe in the Cath Lab
Dr. Sutton reiterated his point: “The number-one message that I want to get across is that it is considered safe for the unborn baby, being in the cath lab, under lead,” she said, noting that there are very good data that the amount of lead that is required by states results in negligible radiation exposure to the developing fetus.
She had her children before working in the cath lab, “but I’ve heard from other women: It’s heavy and its sweaty for prolonged periods of time, but it can be done and you can get through it,” she said. Although the promise of radiation protection systems “is exciting, we have to approach this with some level of caution or awareness,” she said. “Cardiologists come from a cardiology background. We are not radiologists who go through a radiology residency, like IRs do. They get a lot of training on radiation exposure and what it means,” Dr. Sutton stressed.
Dr. Kereiakes, for his part, remains enthusiastic. He returned to the cath lab in August, just 6 months after his brush with near quadriplegia. “This is what I’ve spent my life doing and I love doing it, and I’m not ready to quit.”
Dr. Hermiller, Dr. Kereiakes, and Dr. Sutton reported having no relevant financial conflicts of interest.
A version of this article appeared on Medscape.com.
“I’d probably be a quadriplegic,” Dean J. Kereiakes, MD, an interventional cardiologist, said when asked what would have happened if two top neurosurgeons at his hospital hadn’t rushed him to the operating room (OR) for a cervical decompression in February this year.
Dr. Kereiakes had orthopedic problems for years due to the heavy lead aprons he wore in the cath lab. He regularly dosed himself with steroids for disc pain so he could stand up straight and continue to do procedures. “Several times a year I’d go on a tapering dose of prednisone of about 10 days to 2 weeks, and this would take care of it.”
But then his luck ran out. “I’m told in retrospect that my gait — the way I walked — was different, and I was also having some myoclonic jerking in my legs when I was going to sleep. I thought it was peculiar, but I didn’t really tie it together that this was an upper tract injury response.”
At a restaurant with his wife, he found himself unable to sign the check. “I couldn’t write my name.” By the next morning, “I had a floppy right foot, and as I turned around to put my scrubs on, everything fell apart. My arms began to not function and my legs — I couldn’t walk.”
Admitted to The Christ Hospital Heart & Vascular Center in Cincinnati — the very hospital he works in — Dr. Kereiakes had CT and MRI scans and consulted with neurosurgeons he counts as friends. He was given extremely high doses of intravenous steroids. “But instead of getting better, the pain came back, and I started posturing — when you posture, it looks like a praying mantis, your arms are flexed up, your wrists are flexed, and your fingers are spasmed together.” His wife and the nurses couldn’t pull his fingers open, “so they rolled me back, and the posturing started to go away.”
This prompted the neurosurgeons to bring him to the OR “by 6 a.m., and they are ‘unzipping me in the back’ to basically get my spinal cord off my spine. I had cord compression at C2-3 and C 6-7.”
Postop, Dr. Kereiakes couldn’t move his right leg and couldn’t close any of his fingers. “You lose control of things like bladder and bowel function — you have a catheter in — and you say to yourself, ‘How am I going to live like this?.’ ”
The quick-thinking of his neurosurgeons prevented permanent paralysis, and after a long 6-month recovery, Dr. Kereiakes is back in the cath lab, performing procedures. But crucially, he will no longer have to wear a lead apron.
Ending Careers Early. A Catalyst for Change
Typically, interventional cardiologists, interventional radiologists, electrophysiologists, and others working in labs where they are exposed to ionizing radiation wear lead aprons and garments, such as thyroid collars, leaded caps, and glasses, to protect them during procedures.
Long-term occupational exposure to radiation is linked to cataracts; brain tumors; cancers, including leukemia, multiple myelomas, lymphomas, and thyroid cancers; and left-sided breast cancers in women because the aprons don’t always cover the left side of the chest adequately.
Individual states set the standards in terms of the thickness of the lead required, varying from 0.25- to 0.5-mm–lead-equivalent aprons, which reduce exposure by 85%-95%. Radiation safety officers monitor the badges that staff wear to record their radiation exposure and will warn them when their levels are too high.
But — as Dr. Kereiakes freely admits — ambitious interventionalists don’t always take much notice. “They would come and say, ‘Hey your badge is really high,’ and so I would just put it in a drawer and carry on,” he said. “When you are younger, you feel immortal.”
James B. Hermiller Jr., MD, president of the Society for Cardiovascular Angiography & Interventions (SCAI), agrees: “The feeling is that, with lead, you are indestructible, and no one wants to show any weakness.”
Another occupational hazard related to those protective lead aprons was also being ignored, that of orthopedic injury. In surveys done by SCAI, around half of interventional cardiology respondents report cervical, lumbar, hip, knee, or ankle joint injuries.
While Dr. Kereiakes recognizes likely bias — with those afflicted more likely to complete these surveys — he believes that the problem is huge and “is ending careers early.”
“It’s interesting that radiation is at the forefront of protection and occupational safety, but you are much more likely to be taken out of work because of orthopedic injury,” explained Dr. Hermiller, director of Structural Heart Program at Ascension St. Vincent Heart Center in Indianapolis.
His own story “is not as compelling as Dean’s, but 17 years ago, I ruptured a disk in my lower spine and had emergent surgery and I now need a neck surgery.”
Dr. Hermiller’s hospital, too, has purchased multiple radiation protection systems. “If you want to do this job for 30 years, you have to protect yourself early and at all times,” he said.
His focus as SCAI president is to help get these protection systems in place at more hospitals.
But significant challenges remain, not least the cost, which can be $150,000-$200,000 per lab. He estimates that fewer than 10% US hospitals with cath and other labs using radiation have installed such systems.
Most systems are not US Food and Drug Administration (FDA) approved because they are not attached to equipment in the cath lab, something that Nadia Sutton, MD, MPH, chair of the SCAI Women in Innovations committee, said many physicians are not aware of. “The companies [marketing the systems] are telling us that we can ‘shed our lead,’ ” she said. “It could be safe, but we are using the data provided by the companies.”
How Do the Lead-Free Systems Work?
Currently, there are three main radiation protection systems available. The Protego Radiation Protection System (Image Diagnostics), the EggNest Protect (Egg Medical), and the Rampart (Rampart ic).
According to Dr. Kereiakes, they differ somewhat in whether they allow immediate access to the patient or whether you can see and interact with them. He explained that in high-risk procedures, easy access is desirable. “If you get a perforation or tamponade and the patient suddenly goes ‘out,’ you need to be able to get to them quickly, and you can’t be spending a lot of time taking the shielding down.”
Dr. Kereiakes was recovering in the hospital when his colleagues plumped for the EggNest system. He thinks they chose it because it offers visibility and access to the patient and “takes 4-5 minutes, maximum, to set up.” So far, he agrees with the choice but wants to “give it a real, volume-driven try.”
If they are satisfied with the system, the hospital will order six more by the end of the year, he said. A significant financial undertaking, he acknowledged.
Dr. Hermiller cited data for the Rampart system showing a 95% reduction in radiation without any lead. For an average 1-GRAY radiation exposure case, “if you wear lead, you reach the maximum dose of radiation around 850 cases in a year. If you do it with one of these protection systems, in this case Rampart, you can do 14,500 cases in a year. Not that anyone would do that [many].”
The Protego system has very similar data, he noted. The systems protect the operator and whoever is scrubbing in at the table, so those on the other side of the protector still need to wear lead, Dr. Hermiller stressed.
Data for the EggNest Protect are available but are as yet unpublished.
Dr. Hermiller acknowledged that there is still a long way to go in getting hospitals to spend the money on these systems, but he thinks cath lab operators will drive the change.
“At our SCAI meeting this year, the biggest attendance was at a session about a lead-free cath lab environment.”
Regulation at the State Level
Despite the excitement among the profession, Dr. Sutton — director of Interventional Cardiology Research in the Division of Cardiovascular Medicine at Vanderbilt University Medical Center, Nashville, Tennessee — still has concerns about the lack of FDA regulation.
There is one newer system, called the Radiaction shield system, that attaches to the existing equipment so that is regulated by the FDA as a class II device, she noted. “But it is my understanding that the Protego, Rampart, and EggNest are Class I Exempt. That is the same category as Band-Aid.”
James Beabout, MBA, chief marketing officer, Egg Medical, confirmed that the EggNest “is classified as a Class I device which does not require FDA approval. That leaves regulation to each state regarding the requirements for protective aprons.” And Mark Hansen, vice president business development, of Image Diagnostics — the manufacturer of the Protego Radiation Protection System — confirmed that “the real governance is at the state level.”
The company petitions the state regulator for an exemption letter to the wearing of lead aprons. “In some cases, the state will come to the site directly and validate the systems integrity and to confirm their decision. Once the exemption is granted, the state sends a document, and it’s the responsibility of the sites’ Radiation Safety Officer (RSO) to change the labs safety process and rules,” Mr. Hansen explained.
“What really makes this work is a real-time dosimetry from Fluke Medical. Staff wear one to two badges that instantly detects exposure,” Mr. Hansen stressed.
Similarly, said Mr. Beabout, Egg Medical has data from over 1000 real-world cases collected using real-time dosimetry (RaySafe i3 system) which demonstrate that it is possible to get some people in the room out of protective aprons, where allowed. They recommend real-time dosimetry anytime people are removing their aprons, “since the patient BMI, x-ray system type/age, and complexity of the case all have a significant effect on the radiation dose in each case.” Their goal is for exposure to be zero or as close to zero as possible, “otherwise we recommend use of protective aprons. With the EggNest, operators can use much lighter aprons (0.125 mm sold by Burlington Medical) than what has traditionally been used, so that is also an option,” he said.
Dr. Hermiller said the SCAI plan is to produce several statements on going lead-free, with all other interested professional societies — such as those representing interventional radiologists and vascular surgeons, as well as all the major cardiology societies.
“We want to make an intellectual foundation for this,” Dr. Hermiller explained. Guidelines “are in the making,” he said, with the expectation that they will be ready by the end of this year or early next year.
SCAI will also work with the 50 US states to facilitate lead-free labs, “as each one has a different way to be approved to go without lead,” he noted.
“This is not going to go away, it’s going to build in force, through the societies,” said Dr. Kereiakes. “It’s a matter of workplace safety.” He doesn’t think that the federal Occupational Health and Safety Administration does much to protect doctors, nurses, and technicians in the cath and other labs.
Dr. Hermiller agreed: “I always say that if we were a GM car plant, they would shut us down.”
Dr. Hermiller also stressed the expense of having doctors and other staff off work with occupation-related injuries. He has already observed that “it’s much easier to recruit cath lab staff to a place where they don’t have to wear lead.”
He anticipates that the next generation of physicians “are going to demand places where they don’t have to wear lead.” He is also hopeful that it will result in more women choosing interventional cardiology: “Women are safe in the cath lab with current lead systems, but if we could move to this, there would be even more women participating.”
Pregnancy Safe in the Cath Lab
Dr. Sutton reiterated his point: “The number-one message that I want to get across is that it is considered safe for the unborn baby, being in the cath lab, under lead,” she said, noting that there are very good data that the amount of lead that is required by states results in negligible radiation exposure to the developing fetus.
She had her children before working in the cath lab, “but I’ve heard from other women: It’s heavy and its sweaty for prolonged periods of time, but it can be done and you can get through it,” she said. Although the promise of radiation protection systems “is exciting, we have to approach this with some level of caution or awareness,” she said. “Cardiologists come from a cardiology background. We are not radiologists who go through a radiology residency, like IRs do. They get a lot of training on radiation exposure and what it means,” Dr. Sutton stressed.
Dr. Kereiakes, for his part, remains enthusiastic. He returned to the cath lab in August, just 6 months after his brush with near quadriplegia. “This is what I’ve spent my life doing and I love doing it, and I’m not ready to quit.”
Dr. Hermiller, Dr. Kereiakes, and Dr. Sutton reported having no relevant financial conflicts of interest.
A version of this article appeared on Medscape.com.
“I’d probably be a quadriplegic,” Dean J. Kereiakes, MD, an interventional cardiologist, said when asked what would have happened if two top neurosurgeons at his hospital hadn’t rushed him to the operating room (OR) for a cervical decompression in February this year.
Dr. Kereiakes had orthopedic problems for years due to the heavy lead aprons he wore in the cath lab. He regularly dosed himself with steroids for disc pain so he could stand up straight and continue to do procedures. “Several times a year I’d go on a tapering dose of prednisone of about 10 days to 2 weeks, and this would take care of it.”
But then his luck ran out. “I’m told in retrospect that my gait — the way I walked — was different, and I was also having some myoclonic jerking in my legs when I was going to sleep. I thought it was peculiar, but I didn’t really tie it together that this was an upper tract injury response.”
At a restaurant with his wife, he found himself unable to sign the check. “I couldn’t write my name.” By the next morning, “I had a floppy right foot, and as I turned around to put my scrubs on, everything fell apart. My arms began to not function and my legs — I couldn’t walk.”
Admitted to The Christ Hospital Heart & Vascular Center in Cincinnati — the very hospital he works in — Dr. Kereiakes had CT and MRI scans and consulted with neurosurgeons he counts as friends. He was given extremely high doses of intravenous steroids. “But instead of getting better, the pain came back, and I started posturing — when you posture, it looks like a praying mantis, your arms are flexed up, your wrists are flexed, and your fingers are spasmed together.” His wife and the nurses couldn’t pull his fingers open, “so they rolled me back, and the posturing started to go away.”
This prompted the neurosurgeons to bring him to the OR “by 6 a.m., and they are ‘unzipping me in the back’ to basically get my spinal cord off my spine. I had cord compression at C2-3 and C 6-7.”
Postop, Dr. Kereiakes couldn’t move his right leg and couldn’t close any of his fingers. “You lose control of things like bladder and bowel function — you have a catheter in — and you say to yourself, ‘How am I going to live like this?.’ ”
The quick-thinking of his neurosurgeons prevented permanent paralysis, and after a long 6-month recovery, Dr. Kereiakes is back in the cath lab, performing procedures. But crucially, he will no longer have to wear a lead apron.
Ending Careers Early. A Catalyst for Change
Typically, interventional cardiologists, interventional radiologists, electrophysiologists, and others working in labs where they are exposed to ionizing radiation wear lead aprons and garments, such as thyroid collars, leaded caps, and glasses, to protect them during procedures.
Long-term occupational exposure to radiation is linked to cataracts; brain tumors; cancers, including leukemia, multiple myelomas, lymphomas, and thyroid cancers; and left-sided breast cancers in women because the aprons don’t always cover the left side of the chest adequately.
Individual states set the standards in terms of the thickness of the lead required, varying from 0.25- to 0.5-mm–lead-equivalent aprons, which reduce exposure by 85%-95%. Radiation safety officers monitor the badges that staff wear to record their radiation exposure and will warn them when their levels are too high.
But — as Dr. Kereiakes freely admits — ambitious interventionalists don’t always take much notice. “They would come and say, ‘Hey your badge is really high,’ and so I would just put it in a drawer and carry on,” he said. “When you are younger, you feel immortal.”
James B. Hermiller Jr., MD, president of the Society for Cardiovascular Angiography & Interventions (SCAI), agrees: “The feeling is that, with lead, you are indestructible, and no one wants to show any weakness.”
Another occupational hazard related to those protective lead aprons was also being ignored, that of orthopedic injury. In surveys done by SCAI, around half of interventional cardiology respondents report cervical, lumbar, hip, knee, or ankle joint injuries.
While Dr. Kereiakes recognizes likely bias — with those afflicted more likely to complete these surveys — he believes that the problem is huge and “is ending careers early.”
“It’s interesting that radiation is at the forefront of protection and occupational safety, but you are much more likely to be taken out of work because of orthopedic injury,” explained Dr. Hermiller, director of Structural Heart Program at Ascension St. Vincent Heart Center in Indianapolis.
His own story “is not as compelling as Dean’s, but 17 years ago, I ruptured a disk in my lower spine and had emergent surgery and I now need a neck surgery.”
Dr. Hermiller’s hospital, too, has purchased multiple radiation protection systems. “If you want to do this job for 30 years, you have to protect yourself early and at all times,” he said.
His focus as SCAI president is to help get these protection systems in place at more hospitals.
But significant challenges remain, not least the cost, which can be $150,000-$200,000 per lab. He estimates that fewer than 10% US hospitals with cath and other labs using radiation have installed such systems.
Most systems are not US Food and Drug Administration (FDA) approved because they are not attached to equipment in the cath lab, something that Nadia Sutton, MD, MPH, chair of the SCAI Women in Innovations committee, said many physicians are not aware of. “The companies [marketing the systems] are telling us that we can ‘shed our lead,’ ” she said. “It could be safe, but we are using the data provided by the companies.”
How Do the Lead-Free Systems Work?
Currently, there are three main radiation protection systems available. The Protego Radiation Protection System (Image Diagnostics), the EggNest Protect (Egg Medical), and the Rampart (Rampart ic).
According to Dr. Kereiakes, they differ somewhat in whether they allow immediate access to the patient or whether you can see and interact with them. He explained that in high-risk procedures, easy access is desirable. “If you get a perforation or tamponade and the patient suddenly goes ‘out,’ you need to be able to get to them quickly, and you can’t be spending a lot of time taking the shielding down.”
Dr. Kereiakes was recovering in the hospital when his colleagues plumped for the EggNest system. He thinks they chose it because it offers visibility and access to the patient and “takes 4-5 minutes, maximum, to set up.” So far, he agrees with the choice but wants to “give it a real, volume-driven try.”
If they are satisfied with the system, the hospital will order six more by the end of the year, he said. A significant financial undertaking, he acknowledged.
Dr. Hermiller cited data for the Rampart system showing a 95% reduction in radiation without any lead. For an average 1-GRAY radiation exposure case, “if you wear lead, you reach the maximum dose of radiation around 850 cases in a year. If you do it with one of these protection systems, in this case Rampart, you can do 14,500 cases in a year. Not that anyone would do that [many].”
The Protego system has very similar data, he noted. The systems protect the operator and whoever is scrubbing in at the table, so those on the other side of the protector still need to wear lead, Dr. Hermiller stressed.
Data for the EggNest Protect are available but are as yet unpublished.
Dr. Hermiller acknowledged that there is still a long way to go in getting hospitals to spend the money on these systems, but he thinks cath lab operators will drive the change.
“At our SCAI meeting this year, the biggest attendance was at a session about a lead-free cath lab environment.”
Regulation at the State Level
Despite the excitement among the profession, Dr. Sutton — director of Interventional Cardiology Research in the Division of Cardiovascular Medicine at Vanderbilt University Medical Center, Nashville, Tennessee — still has concerns about the lack of FDA regulation.
There is one newer system, called the Radiaction shield system, that attaches to the existing equipment so that is regulated by the FDA as a class II device, she noted. “But it is my understanding that the Protego, Rampart, and EggNest are Class I Exempt. That is the same category as Band-Aid.”
James Beabout, MBA, chief marketing officer, Egg Medical, confirmed that the EggNest “is classified as a Class I device which does not require FDA approval. That leaves regulation to each state regarding the requirements for protective aprons.” And Mark Hansen, vice president business development, of Image Diagnostics — the manufacturer of the Protego Radiation Protection System — confirmed that “the real governance is at the state level.”
The company petitions the state regulator for an exemption letter to the wearing of lead aprons. “In some cases, the state will come to the site directly and validate the systems integrity and to confirm their decision. Once the exemption is granted, the state sends a document, and it’s the responsibility of the sites’ Radiation Safety Officer (RSO) to change the labs safety process and rules,” Mr. Hansen explained.
“What really makes this work is a real-time dosimetry from Fluke Medical. Staff wear one to two badges that instantly detects exposure,” Mr. Hansen stressed.
Similarly, said Mr. Beabout, Egg Medical has data from over 1000 real-world cases collected using real-time dosimetry (RaySafe i3 system) which demonstrate that it is possible to get some people in the room out of protective aprons, where allowed. They recommend real-time dosimetry anytime people are removing their aprons, “since the patient BMI, x-ray system type/age, and complexity of the case all have a significant effect on the radiation dose in each case.” Their goal is for exposure to be zero or as close to zero as possible, “otherwise we recommend use of protective aprons. With the EggNest, operators can use much lighter aprons (0.125 mm sold by Burlington Medical) than what has traditionally been used, so that is also an option,” he said.
Dr. Hermiller said the SCAI plan is to produce several statements on going lead-free, with all other interested professional societies — such as those representing interventional radiologists and vascular surgeons, as well as all the major cardiology societies.
“We want to make an intellectual foundation for this,” Dr. Hermiller explained. Guidelines “are in the making,” he said, with the expectation that they will be ready by the end of this year or early next year.
SCAI will also work with the 50 US states to facilitate lead-free labs, “as each one has a different way to be approved to go without lead,” he noted.
“This is not going to go away, it’s going to build in force, through the societies,” said Dr. Kereiakes. “It’s a matter of workplace safety.” He doesn’t think that the federal Occupational Health and Safety Administration does much to protect doctors, nurses, and technicians in the cath and other labs.
Dr. Hermiller agreed: “I always say that if we were a GM car plant, they would shut us down.”
Dr. Hermiller also stressed the expense of having doctors and other staff off work with occupation-related injuries. He has already observed that “it’s much easier to recruit cath lab staff to a place where they don’t have to wear lead.”
He anticipates that the next generation of physicians “are going to demand places where they don’t have to wear lead.” He is also hopeful that it will result in more women choosing interventional cardiology: “Women are safe in the cath lab with current lead systems, but if we could move to this, there would be even more women participating.”
Pregnancy Safe in the Cath Lab
Dr. Sutton reiterated his point: “The number-one message that I want to get across is that it is considered safe for the unborn baby, being in the cath lab, under lead,” she said, noting that there are very good data that the amount of lead that is required by states results in negligible radiation exposure to the developing fetus.
She had her children before working in the cath lab, “but I’ve heard from other women: It’s heavy and its sweaty for prolonged periods of time, but it can be done and you can get through it,” she said. Although the promise of radiation protection systems “is exciting, we have to approach this with some level of caution or awareness,” she said. “Cardiologists come from a cardiology background. We are not radiologists who go through a radiology residency, like IRs do. They get a lot of training on radiation exposure and what it means,” Dr. Sutton stressed.
Dr. Kereiakes, for his part, remains enthusiastic. He returned to the cath lab in August, just 6 months after his brush with near quadriplegia. “This is what I’ve spent my life doing and I love doing it, and I’m not ready to quit.”
Dr. Hermiller, Dr. Kereiakes, and Dr. Sutton reported having no relevant financial conflicts of interest.
A version of this article appeared on Medscape.com.
Old, Frail Patients: Study More, Intervene Less?
Lessons From SENIOR-RITA
The ability to save cardiac muscle during an acute coronary syndrome with percutaneous coronary intervention (PCI) made cardiology one of the most popular fields in medicine.
But acute coronary syndromes come in different categories. While rapid PCI clearly benefits patients with ST-segment elevation myocardial infarction (STEMI), the best use of angiography and PCI for patients with non–ST-segment elevation myocardial infarction (NSTEMI) is more complex.
There have been many trials and meta-analyses, and generally, outcomes are similar with either approach. Perhaps if one looks with enough optimism, there is a benefit for the more aggressive approach in higher-risk patients.
Despite the similar outcomes with the two strategies, most patients are treated with the early invasive approach. Early and invasive fit the spirit of modern cardiology.
Yet, older patients with acute coronary syndromes present a different challenge. NSTEMI trials, like most trials, enrolled mostly younger adults.
Whether evidence obtained in young people applies to older patients is one of the most common and important questions in all of medical practice. Older patients may be at higher risk for a primary outcome, but they also have greater risks for harm from therapy as well as more competing causes of morbidity and mortality.
Only a handful of smaller trials have enrolled older patients with NSTEMI. These trials have produced little evidence that an early invasive approach should be preferred.
The SENIOR-RITA Trial
At ESC, Vijay Kunadian, MD, from Newcastle, England, presented results of SENIOR-RITA, a large trial comparing an invasive vs conservative strategy in NSTEMI patients 75 years of age or older.
In the conservative arm, coronary angiography was allowed if the patient deteriorated and the procedure was clinically indicated in the judgment of the treating physicians.
Slightly more than 1500 patients with NSTEMI were randomly assigned to either strategy in 48 centers in the United Kingdom. Their mean age was 82 years, nearly half were women, and about a third were frail.
Over 4 years of follow-up, the primary outcome of cardiovascular (CV) death or MI occurred at a similar rate in both arms: 25.6% vs 26.3% for invasive vs conservative, respectively (HR, 0.94; 95% CI, 0.77-1.14; P =.53).
Rates of CV death were also not significantly different (15.8% vs 14.2%; HR, 1.11; 95% CI, 0.86-1.44).
The rate of nonfatal MI was slightly lower in the invasive arm (11.7% vs 15.0%; HR, 0.75; 95% CI, 0.57-0.99).
Some other notable findings: Fewer than half of patients in the invasive arm underwent revascularization. Coronary angiography was done in about a quarter of patients in the conservative arm, and revascularization in only 14%.
Comments
Because medicine has improved and patients live longer, cardiologists increasingly see older adults with frailty. It’s important to study these patients.
The authors tell us that 1 in 5 patients screened were enrolled, and those not enrolled were similar in age and were treated nearly equally with either strategy. Not all trials offer this information; it’s important because knowing that patients in a trial are representative helps us translate evidence to our actual patients.
Another positive was the investigators’ smart choice of cardiovascular death and MI as their primary outcome. Strategy trials are usually open label. If they had included an outcome that requires a decision from a clinician, such as unplanned revascularization, then bias becomes a possibility when patients and clinicians are aware of the treatment assignment. (I wrote about poor endpoint choice in the ABYSS trial.)
The most notable finding in SENIOR-RITA was that approximately 76% of patients in the conservative arm did not have a coronary angiogram and 86% were not revascularized.
Yet, the rate of CV death and MI were similar during 4 years of follow-up. This observation is nearly identical to the findings in chronic stable disease, seen in the ISCHEMIA trial. (See Figure 6a in the paper’s supplement.)
I take two messages from this consistent observation: One is that medical therapy is quite good at treating coronary artery disease not associated with acute vessel closure in STEMI.
The other is that using coronary angiography and revascularization as a bailout, in only a fraction of cases, achieves the same result, so the conservative strategy should be preferred.
I am not sure that the SENIOR-RITA researchers see it this way. They write in their discussion that “clinicians are often reluctant to offer an invasive strategy to frail older adults.” They then remind readers that modern PCI techniques (radial approach) have low rates of adverse events.
Perhaps I misread their message, but that paragraph seemed like it was reinforcing our tendency to offer invasive approaches to patients with NSTEMI.
I feel differently. When a trial reports similar outcomes with two strategies, I think we should favor the one with less intervention. I feel even more strongly about this philosophy in older patients with frailty.
Are we not in the business of helping people with the least amount of intervention?
The greatest challenge for the cardiologist of today is not a lack of treatment options, but whether we should use all options in older, frailer adults.
Good on the SENIOR-RITA investigators, for they have shown that we can avoid intervention in the vast majority of older adults presenting with NSTEMI.
Dr. Mandrola practices cardiac electrophysiology in Louisville, Kentucky, and is a writer and podcaster for Medscape. He espouses a conservative approach to medical practice. He participates in clinical research and writes often about the state of medical evidence. He has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Lessons From SENIOR-RITA
Lessons From SENIOR-RITA
The ability to save cardiac muscle during an acute coronary syndrome with percutaneous coronary intervention (PCI) made cardiology one of the most popular fields in medicine.
But acute coronary syndromes come in different categories. While rapid PCI clearly benefits patients with ST-segment elevation myocardial infarction (STEMI), the best use of angiography and PCI for patients with non–ST-segment elevation myocardial infarction (NSTEMI) is more complex.
There have been many trials and meta-analyses, and generally, outcomes are similar with either approach. Perhaps if one looks with enough optimism, there is a benefit for the more aggressive approach in higher-risk patients.
Despite the similar outcomes with the two strategies, most patients are treated with the early invasive approach. Early and invasive fit the spirit of modern cardiology.
Yet, older patients with acute coronary syndromes present a different challenge. NSTEMI trials, like most trials, enrolled mostly younger adults.
Whether evidence obtained in young people applies to older patients is one of the most common and important questions in all of medical practice. Older patients may be at higher risk for a primary outcome, but they also have greater risks for harm from therapy as well as more competing causes of morbidity and mortality.
Only a handful of smaller trials have enrolled older patients with NSTEMI. These trials have produced little evidence that an early invasive approach should be preferred.
The SENIOR-RITA Trial
At ESC, Vijay Kunadian, MD, from Newcastle, England, presented results of SENIOR-RITA, a large trial comparing an invasive vs conservative strategy in NSTEMI patients 75 years of age or older.
In the conservative arm, coronary angiography was allowed if the patient deteriorated and the procedure was clinically indicated in the judgment of the treating physicians.
Slightly more than 1500 patients with NSTEMI were randomly assigned to either strategy in 48 centers in the United Kingdom. Their mean age was 82 years, nearly half were women, and about a third were frail.
Over 4 years of follow-up, the primary outcome of cardiovascular (CV) death or MI occurred at a similar rate in both arms: 25.6% vs 26.3% for invasive vs conservative, respectively (HR, 0.94; 95% CI, 0.77-1.14; P =.53).
Rates of CV death were also not significantly different (15.8% vs 14.2%; HR, 1.11; 95% CI, 0.86-1.44).
The rate of nonfatal MI was slightly lower in the invasive arm (11.7% vs 15.0%; HR, 0.75; 95% CI, 0.57-0.99).
Some other notable findings: Fewer than half of patients in the invasive arm underwent revascularization. Coronary angiography was done in about a quarter of patients in the conservative arm, and revascularization in only 14%.
Comments
Because medicine has improved and patients live longer, cardiologists increasingly see older adults with frailty. It’s important to study these patients.
The authors tell us that 1 in 5 patients screened were enrolled, and those not enrolled were similar in age and were treated nearly equally with either strategy. Not all trials offer this information; it’s important because knowing that patients in a trial are representative helps us translate evidence to our actual patients.
Another positive was the investigators’ smart choice of cardiovascular death and MI as their primary outcome. Strategy trials are usually open label. If they had included an outcome that requires a decision from a clinician, such as unplanned revascularization, then bias becomes a possibility when patients and clinicians are aware of the treatment assignment. (I wrote about poor endpoint choice in the ABYSS trial.)
The most notable finding in SENIOR-RITA was that approximately 76% of patients in the conservative arm did not have a coronary angiogram and 86% were not revascularized.
Yet, the rate of CV death and MI were similar during 4 years of follow-up. This observation is nearly identical to the findings in chronic stable disease, seen in the ISCHEMIA trial. (See Figure 6a in the paper’s supplement.)
I take two messages from this consistent observation: One is that medical therapy is quite good at treating coronary artery disease not associated with acute vessel closure in STEMI.
The other is that using coronary angiography and revascularization as a bailout, in only a fraction of cases, achieves the same result, so the conservative strategy should be preferred.
I am not sure that the SENIOR-RITA researchers see it this way. They write in their discussion that “clinicians are often reluctant to offer an invasive strategy to frail older adults.” They then remind readers that modern PCI techniques (radial approach) have low rates of adverse events.
Perhaps I misread their message, but that paragraph seemed like it was reinforcing our tendency to offer invasive approaches to patients with NSTEMI.
I feel differently. When a trial reports similar outcomes with two strategies, I think we should favor the one with less intervention. I feel even more strongly about this philosophy in older patients with frailty.
Are we not in the business of helping people with the least amount of intervention?
The greatest challenge for the cardiologist of today is not a lack of treatment options, but whether we should use all options in older, frailer adults.
Good on the SENIOR-RITA investigators, for they have shown that we can avoid intervention in the vast majority of older adults presenting with NSTEMI.
Dr. Mandrola practices cardiac electrophysiology in Louisville, Kentucky, and is a writer and podcaster for Medscape. He espouses a conservative approach to medical practice. He participates in clinical research and writes often about the state of medical evidence. He has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
The ability to save cardiac muscle during an acute coronary syndrome with percutaneous coronary intervention (PCI) made cardiology one of the most popular fields in medicine.
But acute coronary syndromes come in different categories. While rapid PCI clearly benefits patients with ST-segment elevation myocardial infarction (STEMI), the best use of angiography and PCI for patients with non–ST-segment elevation myocardial infarction (NSTEMI) is more complex.
There have been many trials and meta-analyses, and generally, outcomes are similar with either approach. Perhaps if one looks with enough optimism, there is a benefit for the more aggressive approach in higher-risk patients.
Despite the similar outcomes with the two strategies, most patients are treated with the early invasive approach. Early and invasive fit the spirit of modern cardiology.
Yet, older patients with acute coronary syndromes present a different challenge. NSTEMI trials, like most trials, enrolled mostly younger adults.
Whether evidence obtained in young people applies to older patients is one of the most common and important questions in all of medical practice. Older patients may be at higher risk for a primary outcome, but they also have greater risks for harm from therapy as well as more competing causes of morbidity and mortality.
Only a handful of smaller trials have enrolled older patients with NSTEMI. These trials have produced little evidence that an early invasive approach should be preferred.
The SENIOR-RITA Trial
At ESC, Vijay Kunadian, MD, from Newcastle, England, presented results of SENIOR-RITA, a large trial comparing an invasive vs conservative strategy in NSTEMI patients 75 years of age or older.
In the conservative arm, coronary angiography was allowed if the patient deteriorated and the procedure was clinically indicated in the judgment of the treating physicians.
Slightly more than 1500 patients with NSTEMI were randomly assigned to either strategy in 48 centers in the United Kingdom. Their mean age was 82 years, nearly half were women, and about a third were frail.
Over 4 years of follow-up, the primary outcome of cardiovascular (CV) death or MI occurred at a similar rate in both arms: 25.6% vs 26.3% for invasive vs conservative, respectively (HR, 0.94; 95% CI, 0.77-1.14; P =.53).
Rates of CV death were also not significantly different (15.8% vs 14.2%; HR, 1.11; 95% CI, 0.86-1.44).
The rate of nonfatal MI was slightly lower in the invasive arm (11.7% vs 15.0%; HR, 0.75; 95% CI, 0.57-0.99).
Some other notable findings: Fewer than half of patients in the invasive arm underwent revascularization. Coronary angiography was done in about a quarter of patients in the conservative arm, and revascularization in only 14%.
Comments
Because medicine has improved and patients live longer, cardiologists increasingly see older adults with frailty. It’s important to study these patients.
The authors tell us that 1 in 5 patients screened were enrolled, and those not enrolled were similar in age and were treated nearly equally with either strategy. Not all trials offer this information; it’s important because knowing that patients in a trial are representative helps us translate evidence to our actual patients.
Another positive was the investigators’ smart choice of cardiovascular death and MI as their primary outcome. Strategy trials are usually open label. If they had included an outcome that requires a decision from a clinician, such as unplanned revascularization, then bias becomes a possibility when patients and clinicians are aware of the treatment assignment. (I wrote about poor endpoint choice in the ABYSS trial.)
The most notable finding in SENIOR-RITA was that approximately 76% of patients in the conservative arm did not have a coronary angiogram and 86% were not revascularized.
Yet, the rate of CV death and MI were similar during 4 years of follow-up. This observation is nearly identical to the findings in chronic stable disease, seen in the ISCHEMIA trial. (See Figure 6a in the paper’s supplement.)
I take two messages from this consistent observation: One is that medical therapy is quite good at treating coronary artery disease not associated with acute vessel closure in STEMI.
The other is that using coronary angiography and revascularization as a bailout, in only a fraction of cases, achieves the same result, so the conservative strategy should be preferred.
I am not sure that the SENIOR-RITA researchers see it this way. They write in their discussion that “clinicians are often reluctant to offer an invasive strategy to frail older adults.” They then remind readers that modern PCI techniques (radial approach) have low rates of adverse events.
Perhaps I misread their message, but that paragraph seemed like it was reinforcing our tendency to offer invasive approaches to patients with NSTEMI.
I feel differently. When a trial reports similar outcomes with two strategies, I think we should favor the one with less intervention. I feel even more strongly about this philosophy in older patients with frailty.
Are we not in the business of helping people with the least amount of intervention?
The greatest challenge for the cardiologist of today is not a lack of treatment options, but whether we should use all options in older, frailer adults.
Good on the SENIOR-RITA investigators, for they have shown that we can avoid intervention in the vast majority of older adults presenting with NSTEMI.
Dr. Mandrola practices cardiac electrophysiology in Louisville, Kentucky, and is a writer and podcaster for Medscape. He espouses a conservative approach to medical practice. He participates in clinical research and writes often about the state of medical evidence. He has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Do Cannabis Users Need More Anesthesia During Surgery?
TOPLINE:
However, the clinical relevance of this difference remains unclear.
METHODOLOGY:
- To assess if cannabis use leads to higher doses of inhalational anesthesia during surgery, the researchers conducted a retrospective cohort study comparing the average intraoperative minimum alveolar concentrations of volatile anesthetics (isoflurane and sevoflurane) between older adults who used cannabis products and those who did not.
- The researchers reviewed electronic health records of 22,476 patients aged 65 years or older who underwent surgery at the University of Florida Health System between 2018 and 2020.
- Overall, 268 patients who reported using cannabis within 60 days of surgery (median age, 69 years; 35% women) were matched to 1072 nonusers.
- The median duration of anesthesia was 175 minutes.
- The primary outcome was the intraoperative time-weighted average of isoflurane or sevoflurane minimum alveolar concentration equivalents.
TAKEAWAY:
- Cannabis users had significantly higher average minimum alveolar concentrations of isoflurane or sevoflurane than nonusers (mean, 0.58 vs 0.54; mean difference, 0.04; P = .021).
- The findings were confirmed in a sensitivity analysis that revealed higher mean average minimum alveolar concentrations of anesthesia in cannabis users than in nonusers (0.57 vs 0.53; P = .029).
- Although the 0.04 difference in minimum alveolar concentration between cannabis users and nonusers was statistically significant, its clinical importance is unclear.
IN PRACTICE:
“While recent guidelines underscore the importance of universal screening for cannabinoids before surgery, caution is paramount to prevent clinical bias leading to the administration of unnecessary higher doses of inhalational anesthesia, especially as robust evidence supporting such practices remains lacking,” the authors of the study wrote.
SOURCE:
This study was led by Ruba Sajdeya, MD, PhD, of the Department of Epidemiology at the University of Florida, Gainesville, and was published online in August 2024 in Anesthesiology.
LIMITATIONS:
This study lacked access to prescription or dispensed medications, including opioids, which may have introduced residual confounding. Potential underdocumentation of cannabis use in medical records could have led to exposure misclassification. The causality between cannabis usage and increased anesthetic dosing could not be established due to the observational nature of this study.
DISCLOSURES:
This study was supported by the National Institute on Aging, the National Institutes of Health, and in part by the University of Florida Clinical and Translational Science Institute. Some authors declared receiving research support, consulting fees, and honoraria and having other ties with pharmaceutical companies and various other sources.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
However, the clinical relevance of this difference remains unclear.
METHODOLOGY:
- To assess if cannabis use leads to higher doses of inhalational anesthesia during surgery, the researchers conducted a retrospective cohort study comparing the average intraoperative minimum alveolar concentrations of volatile anesthetics (isoflurane and sevoflurane) between older adults who used cannabis products and those who did not.
- The researchers reviewed electronic health records of 22,476 patients aged 65 years or older who underwent surgery at the University of Florida Health System between 2018 and 2020.
- Overall, 268 patients who reported using cannabis within 60 days of surgery (median age, 69 years; 35% women) were matched to 1072 nonusers.
- The median duration of anesthesia was 175 minutes.
- The primary outcome was the intraoperative time-weighted average of isoflurane or sevoflurane minimum alveolar concentration equivalents.
TAKEAWAY:
- Cannabis users had significantly higher average minimum alveolar concentrations of isoflurane or sevoflurane than nonusers (mean, 0.58 vs 0.54; mean difference, 0.04; P = .021).
- The findings were confirmed in a sensitivity analysis that revealed higher mean average minimum alveolar concentrations of anesthesia in cannabis users than in nonusers (0.57 vs 0.53; P = .029).
- Although the 0.04 difference in minimum alveolar concentration between cannabis users and nonusers was statistically significant, its clinical importance is unclear.
IN PRACTICE:
“While recent guidelines underscore the importance of universal screening for cannabinoids before surgery, caution is paramount to prevent clinical bias leading to the administration of unnecessary higher doses of inhalational anesthesia, especially as robust evidence supporting such practices remains lacking,” the authors of the study wrote.
SOURCE:
This study was led by Ruba Sajdeya, MD, PhD, of the Department of Epidemiology at the University of Florida, Gainesville, and was published online in August 2024 in Anesthesiology.
LIMITATIONS:
This study lacked access to prescription or dispensed medications, including opioids, which may have introduced residual confounding. Potential underdocumentation of cannabis use in medical records could have led to exposure misclassification. The causality between cannabis usage and increased anesthetic dosing could not be established due to the observational nature of this study.
DISCLOSURES:
This study was supported by the National Institute on Aging, the National Institutes of Health, and in part by the University of Florida Clinical and Translational Science Institute. Some authors declared receiving research support, consulting fees, and honoraria and having other ties with pharmaceutical companies and various other sources.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
However, the clinical relevance of this difference remains unclear.
METHODOLOGY:
- To assess if cannabis use leads to higher doses of inhalational anesthesia during surgery, the researchers conducted a retrospective cohort study comparing the average intraoperative minimum alveolar concentrations of volatile anesthetics (isoflurane and sevoflurane) between older adults who used cannabis products and those who did not.
- The researchers reviewed electronic health records of 22,476 patients aged 65 years or older who underwent surgery at the University of Florida Health System between 2018 and 2020.
- Overall, 268 patients who reported using cannabis within 60 days of surgery (median age, 69 years; 35% women) were matched to 1072 nonusers.
- The median duration of anesthesia was 175 minutes.
- The primary outcome was the intraoperative time-weighted average of isoflurane or sevoflurane minimum alveolar concentration equivalents.
TAKEAWAY:
- Cannabis users had significantly higher average minimum alveolar concentrations of isoflurane or sevoflurane than nonusers (mean, 0.58 vs 0.54; mean difference, 0.04; P = .021).
- The findings were confirmed in a sensitivity analysis that revealed higher mean average minimum alveolar concentrations of anesthesia in cannabis users than in nonusers (0.57 vs 0.53; P = .029).
- Although the 0.04 difference in minimum alveolar concentration between cannabis users and nonusers was statistically significant, its clinical importance is unclear.
IN PRACTICE:
“While recent guidelines underscore the importance of universal screening for cannabinoids before surgery, caution is paramount to prevent clinical bias leading to the administration of unnecessary higher doses of inhalational anesthesia, especially as robust evidence supporting such practices remains lacking,” the authors of the study wrote.
SOURCE:
This study was led by Ruba Sajdeya, MD, PhD, of the Department of Epidemiology at the University of Florida, Gainesville, and was published online in August 2024 in Anesthesiology.
LIMITATIONS:
This study lacked access to prescription or dispensed medications, including opioids, which may have introduced residual confounding. Potential underdocumentation of cannabis use in medical records could have led to exposure misclassification. The causality between cannabis usage and increased anesthetic dosing could not be established due to the observational nature of this study.
DISCLOSURES:
This study was supported by the National Institute on Aging, the National Institutes of Health, and in part by the University of Florida Clinical and Translational Science Institute. Some authors declared receiving research support, consulting fees, and honoraria and having other ties with pharmaceutical companies and various other sources.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
Not Kidding: Yellow Dye 5 May Lead to Invisibility
Applying the dye to lab mice made their skin temporarily transparent, allowing Stanford University researchers to observe the rodents’ digestive system, muscle fibers, and blood vessels, according to a study published in Science.
“It’s a stunning result,” said senior author Guosong Hong, PhD, who is assistant professor of materials science and engineering at Stanford University in California. “If the same technique could be applied to humans, it could offer a variety of benefits in biology, diagnostics, and even cosmetics.”
The work drew upon optical concepts first described in the early 20th century to form a surprising theory: Applying a light-absorbing substance could render skin transparent by reducing the chaotic scattering of light as it strikes proteins, fats, and water in tissue.
A search for a suitable light absorber led to FD&C Yellow 5, also called tartrazine, a synthetic color additive certified by the Food and Drug Administration (FDA) for use in foods, cosmetics, and medications.
Rubbed on live mice (after areas of fur were removed using a drugstore depilatory cream), tartrazine rendered skin on their bellies, hind legs, and heads transparent within 5 minutes. With the naked eye, the researchers watched a mouse’s intestines, bladder, and liver at work. Using a microscope, they observed muscle fibers and saw blood vessels in a living mouse’s brain — all without making incisions. Transparency faded quickly when the dye was washed off.
Someday, the concept could be used in doctors’ offices and hospitals, Dr. Hong said.
“Instead of relying on invasive biopsies, doctors might be able to diagnose deep-seated tumors by simply examining a person’s tissue without the need for invasive surgical removal,” he said. “This technique could potentially make blood draws less painful by helping phlebotomists easily locate veins under the skin. It could also enhance procedures like laser tattoo removal by allowing more precise targeting of the pigment beneath the skin.”
From Cake Frosting to Groundbreaking Research
Yellow 5 food dye can be found in everything from cereal, soda, spices, and cake frosting to lipstick, mouthwash, shampoo, dietary supplements, and house paint. Although it’s in some topical medications, more research is needed before it could be used in human diagnostics, said Christopher J. Rowlands, PhD, a senior lecturer in the Department of Bioengineering at Imperial College London, England, where he studies biophotonic instrumentation — ways to image structures inside the body more quickly and clearly.
But the finding could prove useful in research. In a commentary published in Science, Dr. Rowlands and his colleague Jon Gorecki, PhD, an experimental optical physicist also at Imperial College London, noted that the dye could be an alternative to other optical clearing agents currently used in lab studies, such as glycerol, fructose, or acetic acid. Advantages are the effect is reversible and works at lower concentrations with fewer side effects. This could broaden the types of studies possible in lab animals, so researchers don’t have to rely on naturally transparent creatures like nematodes and zebrafish.
The dye could also be paired with imaging techniques such as MRI or electron microscopy.
“Imaging techniques all have pros and cons,” Dr. Rowlands said. “MRI can see all the way through the body albeit with limited resolution and contrast. Electron microscopy has excellent resolution but limited compatibility with live tissue and penetration depth. Optical microscopy has subcellular resolution, the ability to label things, excellent biocompatibility but less than 1 millimeter of penetration depth. This clearing method will give a substantial boost to optical imaging for medicine and biology.”
The discovery could improve the depth imaging equipment can achieve by tenfold, according to the commentary.
Brain research especially stands to benefit. “Neurobiology in particular will have great use for combinations of multiphoton, optogenetics, and tissue clearing to record and control neural activity over (potentially) the whole mouse brain,” he said.
Refraction, Absorption, and The Invisible Man
The dye discovery has distant echoes in H.G. Wells’ 1897 novel The Invisible Man, Dr. Rowlands noted. In the book, a serum makes the main character invisible by changing the light scattering — or refractive index (RI) — of his cells to match the air around him.
The Stanford engineers looked to the past for inspiration, but not to fiction. They turned to a concept first described in the 1920s called the Kramers-Kronig relations, a mathematical principle that can be applied to relationships between the way light is refracted and absorbed in different materials. They also read up on Lorentz oscillation, which describes how electrons and atoms inside molecules react to light.
They reasoned that light-absorbing compounds could equalize the differences between the light-scattering properties of proteins, lipids, and water that make skin opaque.
With that, the search was on. The study’s first author, postdoctoral researcher Zihao Ou, PhD, began testing strong dyes to find a candidate. Tartrazine was a front-runner.
“We found that dye molecules are more efficient in raising the refractive index of water than conventional RI-matching agents, thus resulting in transparency at a much lower concentration,” Dr. Hong said. “The underlying physics, explained by the Lorentz oscillator model and Kramers-Kronig relations, reveals that conventional RI matching agents like fructose are not as efficient because they are not ‘colored’ enough.”
What’s Next
Though the dye is already in products that people consume and apply to their skin, medical use is years away. In some people, tartrazine can cause skin or respiratory reactions.
The National Science Foundation (NSF), which helped fund the research, posted a home or classroom activity related to the work on its website. It involves painting a tartrazine solution on a thin slice of raw chicken breast, making it transparent. The experiment should only be done while wearing a mask, eye protection, lab coat, and lab-quality nitrile gloves for protection, according to the NSF.
Meanwhile, Dr. Hong said his lab is looking for new compounds that will improve visibility through transparent skin, removing a red tone seen in the current experiments. And they’re looking for ways to induce cells to make their own “see-through” compounds.
“We are exploring methods for cells to express intensely absorbing molecules endogenously, enabling genetically encoded tissue transparency in live animals,” he said.
A version of this article first appeared on Medscape.com.
Applying the dye to lab mice made their skin temporarily transparent, allowing Stanford University researchers to observe the rodents’ digestive system, muscle fibers, and blood vessels, according to a study published in Science.
“It’s a stunning result,” said senior author Guosong Hong, PhD, who is assistant professor of materials science and engineering at Stanford University in California. “If the same technique could be applied to humans, it could offer a variety of benefits in biology, diagnostics, and even cosmetics.”
The work drew upon optical concepts first described in the early 20th century to form a surprising theory: Applying a light-absorbing substance could render skin transparent by reducing the chaotic scattering of light as it strikes proteins, fats, and water in tissue.
A search for a suitable light absorber led to FD&C Yellow 5, also called tartrazine, a synthetic color additive certified by the Food and Drug Administration (FDA) for use in foods, cosmetics, and medications.
Rubbed on live mice (after areas of fur were removed using a drugstore depilatory cream), tartrazine rendered skin on their bellies, hind legs, and heads transparent within 5 minutes. With the naked eye, the researchers watched a mouse’s intestines, bladder, and liver at work. Using a microscope, they observed muscle fibers and saw blood vessels in a living mouse’s brain — all without making incisions. Transparency faded quickly when the dye was washed off.
Someday, the concept could be used in doctors’ offices and hospitals, Dr. Hong said.
“Instead of relying on invasive biopsies, doctors might be able to diagnose deep-seated tumors by simply examining a person’s tissue without the need for invasive surgical removal,” he said. “This technique could potentially make blood draws less painful by helping phlebotomists easily locate veins under the skin. It could also enhance procedures like laser tattoo removal by allowing more precise targeting of the pigment beneath the skin.”
From Cake Frosting to Groundbreaking Research
Yellow 5 food dye can be found in everything from cereal, soda, spices, and cake frosting to lipstick, mouthwash, shampoo, dietary supplements, and house paint. Although it’s in some topical medications, more research is needed before it could be used in human diagnostics, said Christopher J. Rowlands, PhD, a senior lecturer in the Department of Bioengineering at Imperial College London, England, where he studies biophotonic instrumentation — ways to image structures inside the body more quickly and clearly.
But the finding could prove useful in research. In a commentary published in Science, Dr. Rowlands and his colleague Jon Gorecki, PhD, an experimental optical physicist also at Imperial College London, noted that the dye could be an alternative to other optical clearing agents currently used in lab studies, such as glycerol, fructose, or acetic acid. Advantages are the effect is reversible and works at lower concentrations with fewer side effects. This could broaden the types of studies possible in lab animals, so researchers don’t have to rely on naturally transparent creatures like nematodes and zebrafish.
The dye could also be paired with imaging techniques such as MRI or electron microscopy.
“Imaging techniques all have pros and cons,” Dr. Rowlands said. “MRI can see all the way through the body albeit with limited resolution and contrast. Electron microscopy has excellent resolution but limited compatibility with live tissue and penetration depth. Optical microscopy has subcellular resolution, the ability to label things, excellent biocompatibility but less than 1 millimeter of penetration depth. This clearing method will give a substantial boost to optical imaging for medicine and biology.”
The discovery could improve the depth imaging equipment can achieve by tenfold, according to the commentary.
Brain research especially stands to benefit. “Neurobiology in particular will have great use for combinations of multiphoton, optogenetics, and tissue clearing to record and control neural activity over (potentially) the whole mouse brain,” he said.
Refraction, Absorption, and The Invisible Man
The dye discovery has distant echoes in H.G. Wells’ 1897 novel The Invisible Man, Dr. Rowlands noted. In the book, a serum makes the main character invisible by changing the light scattering — or refractive index (RI) — of his cells to match the air around him.
The Stanford engineers looked to the past for inspiration, but not to fiction. They turned to a concept first described in the 1920s called the Kramers-Kronig relations, a mathematical principle that can be applied to relationships between the way light is refracted and absorbed in different materials. They also read up on Lorentz oscillation, which describes how electrons and atoms inside molecules react to light.
They reasoned that light-absorbing compounds could equalize the differences between the light-scattering properties of proteins, lipids, and water that make skin opaque.
With that, the search was on. The study’s first author, postdoctoral researcher Zihao Ou, PhD, began testing strong dyes to find a candidate. Tartrazine was a front-runner.
“We found that dye molecules are more efficient in raising the refractive index of water than conventional RI-matching agents, thus resulting in transparency at a much lower concentration,” Dr. Hong said. “The underlying physics, explained by the Lorentz oscillator model and Kramers-Kronig relations, reveals that conventional RI matching agents like fructose are not as efficient because they are not ‘colored’ enough.”
What’s Next
Though the dye is already in products that people consume and apply to their skin, medical use is years away. In some people, tartrazine can cause skin or respiratory reactions.
The National Science Foundation (NSF), which helped fund the research, posted a home or classroom activity related to the work on its website. It involves painting a tartrazine solution on a thin slice of raw chicken breast, making it transparent. The experiment should only be done while wearing a mask, eye protection, lab coat, and lab-quality nitrile gloves for protection, according to the NSF.
Meanwhile, Dr. Hong said his lab is looking for new compounds that will improve visibility through transparent skin, removing a red tone seen in the current experiments. And they’re looking for ways to induce cells to make their own “see-through” compounds.
“We are exploring methods for cells to express intensely absorbing molecules endogenously, enabling genetically encoded tissue transparency in live animals,” he said.
A version of this article first appeared on Medscape.com.
Applying the dye to lab mice made their skin temporarily transparent, allowing Stanford University researchers to observe the rodents’ digestive system, muscle fibers, and blood vessels, according to a study published in Science.
“It’s a stunning result,” said senior author Guosong Hong, PhD, who is assistant professor of materials science and engineering at Stanford University in California. “If the same technique could be applied to humans, it could offer a variety of benefits in biology, diagnostics, and even cosmetics.”
The work drew upon optical concepts first described in the early 20th century to form a surprising theory: Applying a light-absorbing substance could render skin transparent by reducing the chaotic scattering of light as it strikes proteins, fats, and water in tissue.
A search for a suitable light absorber led to FD&C Yellow 5, also called tartrazine, a synthetic color additive certified by the Food and Drug Administration (FDA) for use in foods, cosmetics, and medications.
Rubbed on live mice (after areas of fur were removed using a drugstore depilatory cream), tartrazine rendered skin on their bellies, hind legs, and heads transparent within 5 minutes. With the naked eye, the researchers watched a mouse’s intestines, bladder, and liver at work. Using a microscope, they observed muscle fibers and saw blood vessels in a living mouse’s brain — all without making incisions. Transparency faded quickly when the dye was washed off.
Someday, the concept could be used in doctors’ offices and hospitals, Dr. Hong said.
“Instead of relying on invasive biopsies, doctors might be able to diagnose deep-seated tumors by simply examining a person’s tissue without the need for invasive surgical removal,” he said. “This technique could potentially make blood draws less painful by helping phlebotomists easily locate veins under the skin. It could also enhance procedures like laser tattoo removal by allowing more precise targeting of the pigment beneath the skin.”
From Cake Frosting to Groundbreaking Research
Yellow 5 food dye can be found in everything from cereal, soda, spices, and cake frosting to lipstick, mouthwash, shampoo, dietary supplements, and house paint. Although it’s in some topical medications, more research is needed before it could be used in human diagnostics, said Christopher J. Rowlands, PhD, a senior lecturer in the Department of Bioengineering at Imperial College London, England, where he studies biophotonic instrumentation — ways to image structures inside the body more quickly and clearly.
But the finding could prove useful in research. In a commentary published in Science, Dr. Rowlands and his colleague Jon Gorecki, PhD, an experimental optical physicist also at Imperial College London, noted that the dye could be an alternative to other optical clearing agents currently used in lab studies, such as glycerol, fructose, or acetic acid. Advantages are the effect is reversible and works at lower concentrations with fewer side effects. This could broaden the types of studies possible in lab animals, so researchers don’t have to rely on naturally transparent creatures like nematodes and zebrafish.
The dye could also be paired with imaging techniques such as MRI or electron microscopy.
“Imaging techniques all have pros and cons,” Dr. Rowlands said. “MRI can see all the way through the body albeit with limited resolution and contrast. Electron microscopy has excellent resolution but limited compatibility with live tissue and penetration depth. Optical microscopy has subcellular resolution, the ability to label things, excellent biocompatibility but less than 1 millimeter of penetration depth. This clearing method will give a substantial boost to optical imaging for medicine and biology.”
The discovery could improve the depth imaging equipment can achieve by tenfold, according to the commentary.
Brain research especially stands to benefit. “Neurobiology in particular will have great use for combinations of multiphoton, optogenetics, and tissue clearing to record and control neural activity over (potentially) the whole mouse brain,” he said.
Refraction, Absorption, and The Invisible Man
The dye discovery has distant echoes in H.G. Wells’ 1897 novel The Invisible Man, Dr. Rowlands noted. In the book, a serum makes the main character invisible by changing the light scattering — or refractive index (RI) — of his cells to match the air around him.
The Stanford engineers looked to the past for inspiration, but not to fiction. They turned to a concept first described in the 1920s called the Kramers-Kronig relations, a mathematical principle that can be applied to relationships between the way light is refracted and absorbed in different materials. They also read up on Lorentz oscillation, which describes how electrons and atoms inside molecules react to light.
They reasoned that light-absorbing compounds could equalize the differences between the light-scattering properties of proteins, lipids, and water that make skin opaque.
With that, the search was on. The study’s first author, postdoctoral researcher Zihao Ou, PhD, began testing strong dyes to find a candidate. Tartrazine was a front-runner.
“We found that dye molecules are more efficient in raising the refractive index of water than conventional RI-matching agents, thus resulting in transparency at a much lower concentration,” Dr. Hong said. “The underlying physics, explained by the Lorentz oscillator model and Kramers-Kronig relations, reveals that conventional RI matching agents like fructose are not as efficient because they are not ‘colored’ enough.”
What’s Next
Though the dye is already in products that people consume and apply to their skin, medical use is years away. In some people, tartrazine can cause skin or respiratory reactions.
The National Science Foundation (NSF), which helped fund the research, posted a home or classroom activity related to the work on its website. It involves painting a tartrazine solution on a thin slice of raw chicken breast, making it transparent. The experiment should only be done while wearing a mask, eye protection, lab coat, and lab-quality nitrile gloves for protection, according to the NSF.
Meanwhile, Dr. Hong said his lab is looking for new compounds that will improve visibility through transparent skin, removing a red tone seen in the current experiments. And they’re looking for ways to induce cells to make their own “see-through” compounds.
“We are exploring methods for cells to express intensely absorbing molecules endogenously, enabling genetically encoded tissue transparency in live animals,” he said.
A version of this article first appeared on Medscape.com.
FROM SCIENCE
Cell Phone Use Linked to Higher Heart Disease Risk
“We found that a poor sleep pattern, psychological distress, and neuroticism significantly mediated the positive association between weekly mobile phone usage time and the risk for incident CVD, with a mediating proportion of 5.11%, 11.50%, and 2.25%, respectively,” said principal investigator Xianhui Qin, MD, professor of nephrology at Southern Medical University, Guangzhou, China.
Poor sleep patterns and poor mental health could disrupt circadian rhythms and endocrine and metabolic functions, as well as increase inflammation, he explained.
In addition, chronic exposure to radiofrequency electromagnetic fields (RF-EMF) emitted from cell phones could lead to oxidative stress and an inflammatory response. Combined with smoking and diabetes, this exposure “may have a synergistic effect in increasing CVD risk,” Dr. Qin suggested.
The study was published online in the Canadian Journal of Cardiology.
Risk Underestimated?
The researchers aimed to examine the association of regular cell phone use with incident CVD and explore the mediating effects of sleep and mental health using linked hospital and mortality records.
Their analysis included 444,027 participants (mean age, 56 years; 44% men) without a history of CVD from the UK Biobank. A total of 378,161 participants were regular cell phone users.
Regular cell phone use was defined as at least one call per week. Weekly use was self-reported as the average time of calls per week during the previous 3 months.
The primary outcome was incident CVD. Secondary outcomes were each component of CVD (ie, coronary heart disease, stroke, atrial fibrillation, and heart failure) and increased carotid intima media thickness (CIMT).
Compared with nonregular cell phone users, regular users were younger, had higher proportions of current smokers and urban residents, and had lower proportions of history of hypertension and diabetes. They also had higher income, Townsend deprivation index, and body mass index, and lower education levels.
During a median follow-up of 12.3 years, 56,181 participants developed incident CVD. Compared with nonregular cell phone users, regular users had a significantly higher risk for incident CVD (hazard ratio, 1.04) and increased CIMT (odds ratio, 1.11).
Among regular cell phone users, the duration of cell phone use and hands-free device/speakerphone use during calls was not significantly associated with incident CVD. Yet a significant and positive dose-response relationship was seen between weekly cell phone usage time and the risk for CVD. The positive association was stronger in current vs noncurrent smokers and people with vs without diabetes.
To different extents, sleep patterns (5.11%), psychologic distress (11.5%), and neuroticism (2.25%) mediated the relationship between weekly cell phone usage time and the risk for incident CVD.
“Our study suggests that despite the advantages of mobile phone use, we should also pay attention to the potential harm of mobile phone use to cardiovascular health,” Dr. Qin said. “Future studies to assess the risk-benefit balance will help promote mobile phone use patterns that are conducive to cardiovascular health.”
Meanwhile, he added, “We encourage measures to reduce time spent on mobile phones to promote the primary prevention of CVD. On the other hand, improving sleep and mental health status may help reduce the higher risk of CVD associated with mobile phone use.”
There are several limitations to the study in addition to its observational nature, which cannot show cause and effect. The questionnaires on cell phone use were restricted to phone calls; other use patterns of cell phones (eg, messaging, watching videos, and browsing the web) were not considered. Although the researchers adjusted for many potential confounders, unmeasured confounding bias (eg, the type of cell phone used and other sources of RF-EMF) cannot be eliminated.
Weak Link?
In a comment, Nicholas Grubic, MSc, a PhD student in epidemiology at the University of Toronto, Ontario, Canada, and coauthor of a related editorial, said, “I found it interesting that there was a connection observed between mobile phone use and CVD. However, it is crucial to understand that this link appeared to be much weaker compared with other well-known cardiovascular risk factors, such as smoking, diabetes, and high blood pressure. For now, mobile phone use should not be a major concern for most people.”
Nevertheless, clinicians should encourage patients to practice healthy habits around their screen time, he advised. “This could include limiting mobile phone use before bedtime and taking regular breaks to engage in activities that promote heart health, such as exercising or spending time outdoors.
“For the time being, we probably won’t see mobile phone use included in standard assessments for cardiovascular risk or as a focal point of cardiovascular health promotion initiatives,” he added. Instead, clinicians should “focus on established risk factors that have a stronger impact on patients’ cardiovascular health.”
Nieca Goldberg, MD, a clinical associate professor of medicine at NYU Grossman School of Medicine in New York City and American Heart Association volunteer expert, had a similar message. “You don’t have to go back to using a landline,” she said. “Instead, patients should be more mindful of how much phone use is taking away from their physical activity, keeping them from sleeping, and causing them stress.” Clinicians should also remember to counsel smokers on smoking cessation.
“It would be important for future studies to look at time spent on the phone and the type of activities patients are doing on their phones, such as social media, calls, texts, movies, or streaming TV shows,” she said. “It would be important to see how phone use is leading to a sedentary lifestyle” and what that means for a larger, more diverse population.
The study was supported by the National Key R&D Program, the National Natural Science Foundation of China, and the Outstanding Youth Development Scheme of Nanfang Hospital, Southern Medical University. Dr. Qin, Dr. Grubic, and Dr. Goldberg reported having no relevant financial relationships.
A version of this article first appeared on Medscape.com.
“We found that a poor sleep pattern, psychological distress, and neuroticism significantly mediated the positive association between weekly mobile phone usage time and the risk for incident CVD, with a mediating proportion of 5.11%, 11.50%, and 2.25%, respectively,” said principal investigator Xianhui Qin, MD, professor of nephrology at Southern Medical University, Guangzhou, China.
Poor sleep patterns and poor mental health could disrupt circadian rhythms and endocrine and metabolic functions, as well as increase inflammation, he explained.
In addition, chronic exposure to radiofrequency electromagnetic fields (RF-EMF) emitted from cell phones could lead to oxidative stress and an inflammatory response. Combined with smoking and diabetes, this exposure “may have a synergistic effect in increasing CVD risk,” Dr. Qin suggested.
The study was published online in the Canadian Journal of Cardiology.
Risk Underestimated?
The researchers aimed to examine the association of regular cell phone use with incident CVD and explore the mediating effects of sleep and mental health using linked hospital and mortality records.
Their analysis included 444,027 participants (mean age, 56 years; 44% men) without a history of CVD from the UK Biobank. A total of 378,161 participants were regular cell phone users.
Regular cell phone use was defined as at least one call per week. Weekly use was self-reported as the average time of calls per week during the previous 3 months.
The primary outcome was incident CVD. Secondary outcomes were each component of CVD (ie, coronary heart disease, stroke, atrial fibrillation, and heart failure) and increased carotid intima media thickness (CIMT).
Compared with nonregular cell phone users, regular users were younger, had higher proportions of current smokers and urban residents, and had lower proportions of history of hypertension and diabetes. They also had higher income, Townsend deprivation index, and body mass index, and lower education levels.
During a median follow-up of 12.3 years, 56,181 participants developed incident CVD. Compared with nonregular cell phone users, regular users had a significantly higher risk for incident CVD (hazard ratio, 1.04) and increased CIMT (odds ratio, 1.11).
Among regular cell phone users, the duration of cell phone use and hands-free device/speakerphone use during calls was not significantly associated with incident CVD. Yet a significant and positive dose-response relationship was seen between weekly cell phone usage time and the risk for CVD. The positive association was stronger in current vs noncurrent smokers and people with vs without diabetes.
To different extents, sleep patterns (5.11%), psychologic distress (11.5%), and neuroticism (2.25%) mediated the relationship between weekly cell phone usage time and the risk for incident CVD.
“Our study suggests that despite the advantages of mobile phone use, we should also pay attention to the potential harm of mobile phone use to cardiovascular health,” Dr. Qin said. “Future studies to assess the risk-benefit balance will help promote mobile phone use patterns that are conducive to cardiovascular health.”
Meanwhile, he added, “We encourage measures to reduce time spent on mobile phones to promote the primary prevention of CVD. On the other hand, improving sleep and mental health status may help reduce the higher risk of CVD associated with mobile phone use.”
There are several limitations to the study in addition to its observational nature, which cannot show cause and effect. The questionnaires on cell phone use were restricted to phone calls; other use patterns of cell phones (eg, messaging, watching videos, and browsing the web) were not considered. Although the researchers adjusted for many potential confounders, unmeasured confounding bias (eg, the type of cell phone used and other sources of RF-EMF) cannot be eliminated.
Weak Link?
In a comment, Nicholas Grubic, MSc, a PhD student in epidemiology at the University of Toronto, Ontario, Canada, and coauthor of a related editorial, said, “I found it interesting that there was a connection observed between mobile phone use and CVD. However, it is crucial to understand that this link appeared to be much weaker compared with other well-known cardiovascular risk factors, such as smoking, diabetes, and high blood pressure. For now, mobile phone use should not be a major concern for most people.”
Nevertheless, clinicians should encourage patients to practice healthy habits around their screen time, he advised. “This could include limiting mobile phone use before bedtime and taking regular breaks to engage in activities that promote heart health, such as exercising or spending time outdoors.
“For the time being, we probably won’t see mobile phone use included in standard assessments for cardiovascular risk or as a focal point of cardiovascular health promotion initiatives,” he added. Instead, clinicians should “focus on established risk factors that have a stronger impact on patients’ cardiovascular health.”
Nieca Goldberg, MD, a clinical associate professor of medicine at NYU Grossman School of Medicine in New York City and American Heart Association volunteer expert, had a similar message. “You don’t have to go back to using a landline,” she said. “Instead, patients should be more mindful of how much phone use is taking away from their physical activity, keeping them from sleeping, and causing them stress.” Clinicians should also remember to counsel smokers on smoking cessation.
“It would be important for future studies to look at time spent on the phone and the type of activities patients are doing on their phones, such as social media, calls, texts, movies, or streaming TV shows,” she said. “It would be important to see how phone use is leading to a sedentary lifestyle” and what that means for a larger, more diverse population.
The study was supported by the National Key R&D Program, the National Natural Science Foundation of China, and the Outstanding Youth Development Scheme of Nanfang Hospital, Southern Medical University. Dr. Qin, Dr. Grubic, and Dr. Goldberg reported having no relevant financial relationships.
A version of this article first appeared on Medscape.com.
“We found that a poor sleep pattern, psychological distress, and neuroticism significantly mediated the positive association between weekly mobile phone usage time and the risk for incident CVD, with a mediating proportion of 5.11%, 11.50%, and 2.25%, respectively,” said principal investigator Xianhui Qin, MD, professor of nephrology at Southern Medical University, Guangzhou, China.
Poor sleep patterns and poor mental health could disrupt circadian rhythms and endocrine and metabolic functions, as well as increase inflammation, he explained.
In addition, chronic exposure to radiofrequency electromagnetic fields (RF-EMF) emitted from cell phones could lead to oxidative stress and an inflammatory response. Combined with smoking and diabetes, this exposure “may have a synergistic effect in increasing CVD risk,” Dr. Qin suggested.
The study was published online in the Canadian Journal of Cardiology.
Risk Underestimated?
The researchers aimed to examine the association of regular cell phone use with incident CVD and explore the mediating effects of sleep and mental health using linked hospital and mortality records.
Their analysis included 444,027 participants (mean age, 56 years; 44% men) without a history of CVD from the UK Biobank. A total of 378,161 participants were regular cell phone users.
Regular cell phone use was defined as at least one call per week. Weekly use was self-reported as the average time of calls per week during the previous 3 months.
The primary outcome was incident CVD. Secondary outcomes were each component of CVD (ie, coronary heart disease, stroke, atrial fibrillation, and heart failure) and increased carotid intima media thickness (CIMT).
Compared with nonregular cell phone users, regular users were younger, had higher proportions of current smokers and urban residents, and had lower proportions of history of hypertension and diabetes. They also had higher income, Townsend deprivation index, and body mass index, and lower education levels.
During a median follow-up of 12.3 years, 56,181 participants developed incident CVD. Compared with nonregular cell phone users, regular users had a significantly higher risk for incident CVD (hazard ratio, 1.04) and increased CIMT (odds ratio, 1.11).
Among regular cell phone users, the duration of cell phone use and hands-free device/speakerphone use during calls was not significantly associated with incident CVD. Yet a significant and positive dose-response relationship was seen between weekly cell phone usage time and the risk for CVD. The positive association was stronger in current vs noncurrent smokers and people with vs without diabetes.
To different extents, sleep patterns (5.11%), psychologic distress (11.5%), and neuroticism (2.25%) mediated the relationship between weekly cell phone usage time and the risk for incident CVD.
“Our study suggests that despite the advantages of mobile phone use, we should also pay attention to the potential harm of mobile phone use to cardiovascular health,” Dr. Qin said. “Future studies to assess the risk-benefit balance will help promote mobile phone use patterns that are conducive to cardiovascular health.”
Meanwhile, he added, “We encourage measures to reduce time spent on mobile phones to promote the primary prevention of CVD. On the other hand, improving sleep and mental health status may help reduce the higher risk of CVD associated with mobile phone use.”
There are several limitations to the study in addition to its observational nature, which cannot show cause and effect. The questionnaires on cell phone use were restricted to phone calls; other use patterns of cell phones (eg, messaging, watching videos, and browsing the web) were not considered. Although the researchers adjusted for many potential confounders, unmeasured confounding bias (eg, the type of cell phone used and other sources of RF-EMF) cannot be eliminated.
Weak Link?
In a comment, Nicholas Grubic, MSc, a PhD student in epidemiology at the University of Toronto, Ontario, Canada, and coauthor of a related editorial, said, “I found it interesting that there was a connection observed between mobile phone use and CVD. However, it is crucial to understand that this link appeared to be much weaker compared with other well-known cardiovascular risk factors, such as smoking, diabetes, and high blood pressure. For now, mobile phone use should not be a major concern for most people.”
Nevertheless, clinicians should encourage patients to practice healthy habits around their screen time, he advised. “This could include limiting mobile phone use before bedtime and taking regular breaks to engage in activities that promote heart health, such as exercising or spending time outdoors.
“For the time being, we probably won’t see mobile phone use included in standard assessments for cardiovascular risk or as a focal point of cardiovascular health promotion initiatives,” he added. Instead, clinicians should “focus on established risk factors that have a stronger impact on patients’ cardiovascular health.”
Nieca Goldberg, MD, a clinical associate professor of medicine at NYU Grossman School of Medicine in New York City and American Heart Association volunteer expert, had a similar message. “You don’t have to go back to using a landline,” she said. “Instead, patients should be more mindful of how much phone use is taking away from their physical activity, keeping them from sleeping, and causing them stress.” Clinicians should also remember to counsel smokers on smoking cessation.
“It would be important for future studies to look at time spent on the phone and the type of activities patients are doing on their phones, such as social media, calls, texts, movies, or streaming TV shows,” she said. “It would be important to see how phone use is leading to a sedentary lifestyle” and what that means for a larger, more diverse population.
The study was supported by the National Key R&D Program, the National Natural Science Foundation of China, and the Outstanding Youth Development Scheme of Nanfang Hospital, Southern Medical University. Dr. Qin, Dr. Grubic, and Dr. Goldberg reported having no relevant financial relationships.
A version of this article first appeared on Medscape.com.
FROM THE CANADIAN JOURNAL OF CARDIOLOGY