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SAN DIEGO – The “holy grail” of thrombosis prevention is the ability to determine the risk of recurrence with or without continuation of anticoagulant treatment, according to Philip S. Wells, MD.
“Very little data exists for the comparison of active treatment to placebo in the acute and long-term phases of treatment,” he said at the biennial summit of the Thrombosis & Hemostasis Societies of North America. “With low molecular weight heparin, vitamin K antagonists, and direct-acting oral anticoagulants, the relative risk reduction is about 90% in the acute phase and 80%-85% in the extended phase. After discontinuing anticoagulants, the absolute risk of recurrence varies depending on VTE category.”
Dr. Wells, chair and chief of the department of medicine at The Ottawa Hospital and the University of Ottawa, said that after 3 months of anticoagulation the chance of recurrence in postsurgical VTE patients is less than 1% per year. After 3 months of anticoagulant use in nonsurgical patients with provoked risk factors, it is around 4%. This includes medical patients, trauma victims, pregnant women, and patients wearing a plaster cast.
In patients who survive an unprovoked VTE, after 3-6 months of anticoagulant therapy their overall recurrence risk is 10% in the first year and 30% after 5 years. The risk of recurrence is 50% higher if a patient experiences a second unprovoked VTE, and the risk of fatality is 50% higher if the initial event was a pulmonary embolism (PE), he said.
According to the ongoing prospective Austrian Study on Recurrent Venous Thromboembolism, the risk of recurrent VTE is 20% in men and 6% in women (N Engl J Med. 2004 Jun 17;350[25]:2558-63). A multicenter prospective study in Canada yielded similar results. It found that the risk of recurrent VTE is 19% in men versus 9% in women (CMAJ 2008;179[5]:417-26).
That Canadian prospective study, led by Marc Rodger, MD, described the development of the HERDOO2 clinical decision rule for determining a patient’s risk for a recurrent VTE. This includes hyperpigmentation, edema, or redness in either leg (signs of postthrombotic syndrome), D-dimer level of 250 mcg/L or greater while on warfarin, body mass index of 30 kg/m2 or greater, and age of 65 years or older.
If patients have zero or one risk factor, the annual risk of VTE after 6 months of treatment is 1.6%, while two or more risk factors bumps the annual risk of VTE to 14.1%, according to the researchers.
In a subsequent study to validate the HERDOO2, researchers found that the risk of recurrent major VTE was 3.0% in low-risk women who discontinued oral anticoagulants (OACs), 8.1% in high-risk women and men who discontinued OACs, 1.6% in high-risk women and men who continued OACs, and 7.4% in high-risk women who discontinued OACs (BMJ 2017;356:j1065).
“I think the HERDOO2 rule is working pretty well to determine a low-risk group of women, and it’s not an unreasonable tool to be using,” Dr. Wells said.
Other variables that might help clinicians predict a patient’s VTE recurrence include the presence of recurrent venous obstruction (adjusted HR 1.32), and older age (HR 1.01 for every 1 year increase).
D-dimer levels can also be helpful. “If the serial D-dimers are positive, stay on anticoagulants,” Dr. Wells advised. “If they’re negative, discontinue anticoagulants and have the D-dimer levels repeated monthly for 3 months. If positive or positive conversions, return to OAC therapy.”
In one study, the annual risk of a VTE was 3% in the negative D-dimer patients, compared with 6.1% in those who had a history of an unprovoked VTE (Blood 2014;124:196-203).
In a separate study of 319 patients with two negative D-dimer results who did not restart anticoagulation therapy, the rate of recurrent VTE was 6.7% per patient-year (Ann Intern Med 2015;162:27-34). It was 9.7% per patient-year in men, compared with 5.4% per patient-year in women.
Dr. Wells emphasized the importance of shared decision-making with the patient when devising a strategy for long-term anticoagulation following a VTE. “We don’t have a lot of good tools, but [trying to elicit] patient preference is the right thing to try and do,” he said. “Physicians should present an unbiased perspective to patients regarding their treatment, including the benefits and harms, effect on quality of life, and cost.”
Dr. Wells also shared his current clinical approach. In women with an unprovoked VTE, he applies the HERDOO2 rule. If there’s a low recurrence risk, he discontinues the anticoagulant. If there’s a non-low recurrence risk he continues with the anticoagulant unless there’s a high risk for bleeding. Men with an unprovoked VTE receive indefinite anticoagulant therapy, but if the index event is a deep vein thrombosis (DVT), Dr. Wells applies a bleeding risk tool to help him determine management going forward. If the patient has a high risk of bleeding, he does not use an anticoagulant.
“If there is a high risk of bleeding it’s best of stay off anticoagulant therapy,” he said. “If there is an intermediate risk of bleeding and the index event was a DVT, the patient could stay off anticoagulants. I think we have a long way to go to developing tools that actually enable us to reach these points with each patient in discussions we have with them about continuing anticoagulants.”
Dr. Wells reported having received research support from BMS/Pfizer and honoraria from Bayer AG, Janssen, Pfizer, and Daiichi Sankyo. He is a member of the scientific advisory board for Bayer AG and Pfizer.
SAN DIEGO – The “holy grail” of thrombosis prevention is the ability to determine the risk of recurrence with or without continuation of anticoagulant treatment, according to Philip S. Wells, MD.
“Very little data exists for the comparison of active treatment to placebo in the acute and long-term phases of treatment,” he said at the biennial summit of the Thrombosis & Hemostasis Societies of North America. “With low molecular weight heparin, vitamin K antagonists, and direct-acting oral anticoagulants, the relative risk reduction is about 90% in the acute phase and 80%-85% in the extended phase. After discontinuing anticoagulants, the absolute risk of recurrence varies depending on VTE category.”
Dr. Wells, chair and chief of the department of medicine at The Ottawa Hospital and the University of Ottawa, said that after 3 months of anticoagulation the chance of recurrence in postsurgical VTE patients is less than 1% per year. After 3 months of anticoagulant use in nonsurgical patients with provoked risk factors, it is around 4%. This includes medical patients, trauma victims, pregnant women, and patients wearing a plaster cast.
In patients who survive an unprovoked VTE, after 3-6 months of anticoagulant therapy their overall recurrence risk is 10% in the first year and 30% after 5 years. The risk of recurrence is 50% higher if a patient experiences a second unprovoked VTE, and the risk of fatality is 50% higher if the initial event was a pulmonary embolism (PE), he said.
According to the ongoing prospective Austrian Study on Recurrent Venous Thromboembolism, the risk of recurrent VTE is 20% in men and 6% in women (N Engl J Med. 2004 Jun 17;350[25]:2558-63). A multicenter prospective study in Canada yielded similar results. It found that the risk of recurrent VTE is 19% in men versus 9% in women (CMAJ 2008;179[5]:417-26).
That Canadian prospective study, led by Marc Rodger, MD, described the development of the HERDOO2 clinical decision rule for determining a patient’s risk for a recurrent VTE. This includes hyperpigmentation, edema, or redness in either leg (signs of postthrombotic syndrome), D-dimer level of 250 mcg/L or greater while on warfarin, body mass index of 30 kg/m2 or greater, and age of 65 years or older.
If patients have zero or one risk factor, the annual risk of VTE after 6 months of treatment is 1.6%, while two or more risk factors bumps the annual risk of VTE to 14.1%, according to the researchers.
In a subsequent study to validate the HERDOO2, researchers found that the risk of recurrent major VTE was 3.0% in low-risk women who discontinued oral anticoagulants (OACs), 8.1% in high-risk women and men who discontinued OACs, 1.6% in high-risk women and men who continued OACs, and 7.4% in high-risk women who discontinued OACs (BMJ 2017;356:j1065).
“I think the HERDOO2 rule is working pretty well to determine a low-risk group of women, and it’s not an unreasonable tool to be using,” Dr. Wells said.
Other variables that might help clinicians predict a patient’s VTE recurrence include the presence of recurrent venous obstruction (adjusted HR 1.32), and older age (HR 1.01 for every 1 year increase).
D-dimer levels can also be helpful. “If the serial D-dimers are positive, stay on anticoagulants,” Dr. Wells advised. “If they’re negative, discontinue anticoagulants and have the D-dimer levels repeated monthly for 3 months. If positive or positive conversions, return to OAC therapy.”
In one study, the annual risk of a VTE was 3% in the negative D-dimer patients, compared with 6.1% in those who had a history of an unprovoked VTE (Blood 2014;124:196-203).
In a separate study of 319 patients with two negative D-dimer results who did not restart anticoagulation therapy, the rate of recurrent VTE was 6.7% per patient-year (Ann Intern Med 2015;162:27-34). It was 9.7% per patient-year in men, compared with 5.4% per patient-year in women.
Dr. Wells emphasized the importance of shared decision-making with the patient when devising a strategy for long-term anticoagulation following a VTE. “We don’t have a lot of good tools, but [trying to elicit] patient preference is the right thing to try and do,” he said. “Physicians should present an unbiased perspective to patients regarding their treatment, including the benefits and harms, effect on quality of life, and cost.”
Dr. Wells also shared his current clinical approach. In women with an unprovoked VTE, he applies the HERDOO2 rule. If there’s a low recurrence risk, he discontinues the anticoagulant. If there’s a non-low recurrence risk he continues with the anticoagulant unless there’s a high risk for bleeding. Men with an unprovoked VTE receive indefinite anticoagulant therapy, but if the index event is a deep vein thrombosis (DVT), Dr. Wells applies a bleeding risk tool to help him determine management going forward. If the patient has a high risk of bleeding, he does not use an anticoagulant.
“If there is a high risk of bleeding it’s best of stay off anticoagulant therapy,” he said. “If there is an intermediate risk of bleeding and the index event was a DVT, the patient could stay off anticoagulants. I think we have a long way to go to developing tools that actually enable us to reach these points with each patient in discussions we have with them about continuing anticoagulants.”
Dr. Wells reported having received research support from BMS/Pfizer and honoraria from Bayer AG, Janssen, Pfizer, and Daiichi Sankyo. He is a member of the scientific advisory board for Bayer AG and Pfizer.
SAN DIEGO – The “holy grail” of thrombosis prevention is the ability to determine the risk of recurrence with or without continuation of anticoagulant treatment, according to Philip S. Wells, MD.
“Very little data exists for the comparison of active treatment to placebo in the acute and long-term phases of treatment,” he said at the biennial summit of the Thrombosis & Hemostasis Societies of North America. “With low molecular weight heparin, vitamin K antagonists, and direct-acting oral anticoagulants, the relative risk reduction is about 90% in the acute phase and 80%-85% in the extended phase. After discontinuing anticoagulants, the absolute risk of recurrence varies depending on VTE category.”
Dr. Wells, chair and chief of the department of medicine at The Ottawa Hospital and the University of Ottawa, said that after 3 months of anticoagulation the chance of recurrence in postsurgical VTE patients is less than 1% per year. After 3 months of anticoagulant use in nonsurgical patients with provoked risk factors, it is around 4%. This includes medical patients, trauma victims, pregnant women, and patients wearing a plaster cast.
In patients who survive an unprovoked VTE, after 3-6 months of anticoagulant therapy their overall recurrence risk is 10% in the first year and 30% after 5 years. The risk of recurrence is 50% higher if a patient experiences a second unprovoked VTE, and the risk of fatality is 50% higher if the initial event was a pulmonary embolism (PE), he said.
According to the ongoing prospective Austrian Study on Recurrent Venous Thromboembolism, the risk of recurrent VTE is 20% in men and 6% in women (N Engl J Med. 2004 Jun 17;350[25]:2558-63). A multicenter prospective study in Canada yielded similar results. It found that the risk of recurrent VTE is 19% in men versus 9% in women (CMAJ 2008;179[5]:417-26).
That Canadian prospective study, led by Marc Rodger, MD, described the development of the HERDOO2 clinical decision rule for determining a patient’s risk for a recurrent VTE. This includes hyperpigmentation, edema, or redness in either leg (signs of postthrombotic syndrome), D-dimer level of 250 mcg/L or greater while on warfarin, body mass index of 30 kg/m2 or greater, and age of 65 years or older.
If patients have zero or one risk factor, the annual risk of VTE after 6 months of treatment is 1.6%, while two or more risk factors bumps the annual risk of VTE to 14.1%, according to the researchers.
In a subsequent study to validate the HERDOO2, researchers found that the risk of recurrent major VTE was 3.0% in low-risk women who discontinued oral anticoagulants (OACs), 8.1% in high-risk women and men who discontinued OACs, 1.6% in high-risk women and men who continued OACs, and 7.4% in high-risk women who discontinued OACs (BMJ 2017;356:j1065).
“I think the HERDOO2 rule is working pretty well to determine a low-risk group of women, and it’s not an unreasonable tool to be using,” Dr. Wells said.
Other variables that might help clinicians predict a patient’s VTE recurrence include the presence of recurrent venous obstruction (adjusted HR 1.32), and older age (HR 1.01 for every 1 year increase).
D-dimer levels can also be helpful. “If the serial D-dimers are positive, stay on anticoagulants,” Dr. Wells advised. “If they’re negative, discontinue anticoagulants and have the D-dimer levels repeated monthly for 3 months. If positive or positive conversions, return to OAC therapy.”
In one study, the annual risk of a VTE was 3% in the negative D-dimer patients, compared with 6.1% in those who had a history of an unprovoked VTE (Blood 2014;124:196-203).
In a separate study of 319 patients with two negative D-dimer results who did not restart anticoagulation therapy, the rate of recurrent VTE was 6.7% per patient-year (Ann Intern Med 2015;162:27-34). It was 9.7% per patient-year in men, compared with 5.4% per patient-year in women.
Dr. Wells emphasized the importance of shared decision-making with the patient when devising a strategy for long-term anticoagulation following a VTE. “We don’t have a lot of good tools, but [trying to elicit] patient preference is the right thing to try and do,” he said. “Physicians should present an unbiased perspective to patients regarding their treatment, including the benefits and harms, effect on quality of life, and cost.”
Dr. Wells also shared his current clinical approach. In women with an unprovoked VTE, he applies the HERDOO2 rule. If there’s a low recurrence risk, he discontinues the anticoagulant. If there’s a non-low recurrence risk he continues with the anticoagulant unless there’s a high risk for bleeding. Men with an unprovoked VTE receive indefinite anticoagulant therapy, but if the index event is a deep vein thrombosis (DVT), Dr. Wells applies a bleeding risk tool to help him determine management going forward. If the patient has a high risk of bleeding, he does not use an anticoagulant.
“If there is a high risk of bleeding it’s best of stay off anticoagulant therapy,” he said. “If there is an intermediate risk of bleeding and the index event was a DVT, the patient could stay off anticoagulants. I think we have a long way to go to developing tools that actually enable us to reach these points with each patient in discussions we have with them about continuing anticoagulants.”
Dr. Wells reported having received research support from BMS/Pfizer and honoraria from Bayer AG, Janssen, Pfizer, and Daiichi Sankyo. He is a member of the scientific advisory board for Bayer AG and Pfizer.
EXPERT ANALYSIS FROM THSNA 2018