Leonard S. Feldman, MD

Secondary to rising healthcare costs in the United States, broad efforts are underway to identify and reduce waste in the health system.1,2 A recent systematic review exhibited that many physicians inaccurately estimate the cost of medications.3 Raising awareness of medication costs among prescribers is one potential way to promote high-value care.

Some evidence suggests that cost transparency may help prescribers understand how medication orders drive costs. In a previous study carried out at the Johns Hopkins Hospital, fee data were displayed to providers for diagnostic laboratory tests.4 An 8.6% decrease (95% confidence interval [CI], –8.99% to –8.19%) in test ordering was observed when costs were displayed vs a 5.6% increase (95% CI, 4.90% to 6.39%) in ordering when costs were not displayed during a 6-month intervention period (P < 0.001). Conversely, a similar study that investigated the impact of cost transparency on inpatient imaging utilization did not demonstrate a significant influence of cost display.5 This suggests that cost transparency may work in some areas of care but not in others. A systematic review that investigated price-display interventions for imaging, laboratory studies, and medications reported 10 studies that demonstrated a statistically significant decrease in expenditures without an effect on patient safety.6

Informing prescribers of institution-specific medication costs within and between drug classes may enable the selection of less expensive, therapeutically equivalent drugs. Prior studies investigating the effect of medication cost display were conducted in a variety of patient care settings, including ambulatory clinics,7 urgent care centers,8 and operating rooms,9^,10 with some yielding positive results in terms of ordering and cost11^,12 and others having no impact.13^,14 Currently, there is little evidence specifically addressing the effect of cost display for medications in the inpatient setting.

As part of an institutional initiative to control pharmaceutical expenditures, informational messaging for several high-cost drugs was initiated at our tertiary care hospital in April 2015. The goal of our study was to assess the effect of these medication cost messages on ordering practices. We hypothesized that the display of inpatient pharmaceutical costs at the time of order entry would result in a reduction in ordering.

Setting, Intervention, and Participants

As part of an effort to educate prescribers about the high cost of medications, 9 intravenous (IV) medications were selected by the Johns Hopkins Hospital Pharmacy and Therapeutics Committee as targets for drug cost messaging. The intention of the committee was to implement a rapid, low-cost, proof-of-concept, quality-improvement project that was not designed as prospective research. Representatives from the pharmacy and clinicians from relevant clinical areas participated in preimplementation discussions to help identify medications that were subjectively felt to be overused at our institution and potentially modifiable through provider education. The criteria for selecting drug targets included a variety of factors, such as medications infrequently ordered but representing a significant cost per dose (eg, eculizumab and ribavirin), frequently ordered medications with less expensive substitutes (eg, linezolid and voriconazole), and high-cost medications without direct therapeutic alternatives (eg, calcitonin). From April 10, 2015, to October 5, 2015, the computerized Provider Order Entry System (cPOE), Sunrise Clinical Manager (Allscripts Corporation, Chicago, IL), displayed the cost for targeted medications. Seven of the medication alerts also included a reasonable therapeutic alternative and its cost. There were no restrictions placed on ordering; prescribers were able to choose the high-cost medications at their discretion.

Despite the fact that this initiative was not designed as a research project, we felt it was important to formally evaluate the impact of the drug cost messaging effort to inform future quality-improvement interventions. Each medication was compared to its preintervention baseline utilization dating back to January 1, 2013. For the 7 medications with alternatives offered, we also analyzed use of the suggested alternative during these time periods.

Data Sources and Measurement

Our study utilized data obtained from the pharmacy order verification system and the cPOE database. Data were collected over a period of 143 weeks from January 1, 2013, to October 5, 2015, to allow for a baseline period (January 1, 2013, to April 9, 2015) and an intervention period (April 10, 2015, to October 5, 2015). Data elements extracted included drug characteristics (dosage form, route, cost, strength, name, and quantity), patient characteristics (race, gender, and age), clinical setting (facility location, inpatient or outpatient), and billing information (provider name, doses dispensed from pharmacy, order number, revenue or procedure code, record number, date of service, and unique billing number) for each admission. Using these elements, we generated the following 8 variables to use in our analyses: week, month, period identifier, drug name, dosage form, weekly orders, weekly patient days, and number of weekly orders per 10,000 patient days. Average wholesale price (AWP), referred to as medication cost in this manuscript, was used to report all drug costs in all associated cost calculations. While the actual cost of acquisition and price charged to the patient may vary based on several factors, including manufacturer and payer, we chose to use AWP as a generalizable estimate of the cost of acquisition of the drug for the hospital.

Variables

“Week” and “month” were defined as the week and month of our study, respectively. The “period identifier” was a binary variable that identified the time period before and after the intervention. “Weekly orders” was defined as the total number of new orders placed per week for each specified drug included in our study. For example, if a patient received 2 discrete, new orders for a medication in a given week, 2 orders would be counted toward the “weekly orders” variable. “Patient days,” defined as the total number of patients treated at our facility, was summated for each week of our study to yield “weekly patient days.” To derive the “number of weekly orders per 10,000 patient days,” we divided weekly orders by weekly patient days and multiplied the resultant figure by 10,000.

Statistical Analysis

Segmented regression, a form of interrupted time series analysis, is a quasi-experimental design that was used to determine the immediate and sustained effects of the drug cost messages on the rate of medication ordering.^15-17 The model enabled the use of comparison groups (alternative medications, as described above) to enhance internal validity.

In time series data, outcomes may not be independent over time. Autocorrelation of the error terms can arise when outcomes are more similar at time points closer together than outcomes at time points further apart. Failure to account for autocorrelation of the error terms may lead to underestimated standard errors. The presence of autocorrelation, assessed by calculating the Durbin-Watson statistic, was significant among our data. To adjust for this, we employed a Prais-Winsten estimation to adjust the error term (ε_t) calculated in our models.

Two segmented linear regression models were used to estimate trends in ordering before and after the intervention. The presence or absence of a comparator drug determined which model was to be used. When only single medications were under study, as in the case of eculizumab and calcitonin, our regression model was as follows:

Y_t = (β₀) + (β₁)(Time_t) + (β₂)(Intervention_t) + (β₃)(Post-Intervention Time_t) + (ε_t)

In our single-drug model, Y_t denoted the number of orders per 10,000 patient days at week “t”; Time_t was a continuous variable that indicated the number of weeks prior to or after the study intervention (April 10, 2015) and ranged from –116 to 27 weeks. Post-Intervention Time_t was a continuous variable that denoted the number of weeks since the start of the intervention and is coded as zero for all time periods prior to the intervention. β₀ was the estimated baseline number of orders per 10,000 patient days at the beginning of the study. β₁ is the trend of orders per 10,000 patient days per week during the preintervention period; β₂ represents an estimate of the change in the number of orders per 10,000 patient days immediately after the intervention; β₃ denotes the difference between preintervention and postintervention slopes; and ε_t is the “error term,” which represents autocorrelation and random variability of the data.

As mentioned previously, alternative dosage forms of 7 medications included in our study were utilized as comparison groups. In these instances (when multiple drugs were included in our analyses), the following regression model was applied:

Y _t = ( β ₀ ) + ( β ₁ )(Time _t ) + ( β ₂ )(Intervention _t ) + ( β ₃ )(Post-Intervention Time _t ) + ( β ₄ )(Cohort) + ( β ₅ )(Cohort)(Time _t ) + ( β ₆ )(Cohort)(Intervention _t ) + ( β ₇ )(Cohort)(Post-Intervention Time _t ) + ( ε _t )

Here, 3 coefficients were added (β₄-β₇) to describe an additional cohort of orders. Cohort, a binary indicator variable, held a value of either 0 or 1 when the model was used to describe the treatment or comparison group, respectively. The coefficients β₄-β₇ described the treatment group, and β₀-β₃ described the comparison group. β₄ was the difference in the number of baseline orders per 10,000 patient days between treatment and comparison groups; Β₅ represented the difference between the estimated ordering trends of treatment and comparison groups; and Β₆ indicated the difference in immediate changes in the number of orders per 10,000 patient days in the 2 groups following the intervention.

The number of orders per week was recorded for each medicine, which enabled a large number of data points to be included in our analyses. This allowed for more accurate and stable estimates to be made in our regression model. A total of 143 data points were collected for each study group, 116 before and 27 following each intervention.

All analyses were conducted by using STATA version 13.1 (StataCorp LP, College Station, TX).

Initial results pertaining to 9 IV medications were examined (Table). Following the implementation of cost messaging, no significant changes were observed in order frequency or trend for IV formulations of eculizumab, calcitonin, levetiracetam, linezolid, mycophenolate, ribavirin, voriconazole, and levothyroxine (Figures 1 and 2). However, a significant decrease in the number of oral ribavirin orders (Figure 2), the control group for the IV form, was observed (–16.3 orders per 10,000 patient days; P = .004; 95% CI, –27.2 to –5.31).

Our results suggest that the passive strategy of displaying cost alone was not effective in altering prescriber ordering patterns for the selected medications. This may be due to a lack of awareness regarding direct financial impact on the patient, importance of costs in medical decision-making, or a perceived lack of alternatives or suitability of recommended alternatives. These results may prove valuable to hospital and pharmacy leadership as they develop strategies to curb medication expense.

Changes observed in IV pantoprazole ordering are instructive. Due to a national shortage, the IV form of this medication underwent a restriction, which required approval by the pharmacy prior to dispensing. This restriction was instituted independently of our study and led to a 73% decrease from usage rates prior to policy implementation (Figure 3). Ordering was restricted according to defined criteria for IV use. The restriction did not apply to oral pantoprazole, and no significant change in ordering of the oral formulation was noted during the evaluated period (Figure 3).

Disclosures: The authors state that there were no external sponsors for this work. The Johns Hopkins Hospital and University “funded” this work by paying the salaries of the authors. The author team maintained independence and made all decisions regarding the study design, data collection, data analysis, interpretation of results, writing of the research report, and decision to submit it for publication. Dr. Shermock had full access to all the study data and takes responsibility for the integrity of the data and accuracy of the data analysis.

Secondary to rising healthcare costs in the United States, broad efforts are underway to identify and reduce waste in the health system.1,2 A recent systematic review exhibited that many physicians inaccurately estimate the cost of medications.3 Raising awareness of medication costs among prescribers is one potential way to promote high-value care.

Some evidence suggests that cost transparency may help prescribers understand how medication orders drive costs. In a previous study carried out at the Johns Hopkins Hospital, fee data were displayed to providers for diagnostic laboratory tests.4 An 8.6% decrease (95% confidence interval [CI], –8.99% to –8.19%) in test ordering was observed when costs were displayed vs a 5.6% increase (95% CI, 4.90% to 6.39%) in ordering when costs were not displayed during a 6-month intervention period (P < 0.001). Conversely, a similar study that investigated the impact of cost transparency on inpatient imaging utilization did not demonstrate a significant influence of cost display.5 This suggests that cost transparency may work in some areas of care but not in others. A systematic review that investigated price-display interventions for imaging, laboratory studies, and medications reported 10 studies that demonstrated a statistically significant decrease in expenditures without an effect on patient safety.6

Informing prescribers of institution-specific medication costs within and between drug classes may enable the selection of less expensive, therapeutically equivalent drugs. Prior studies investigating the effect of medication cost display were conducted in a variety of patient care settings, including ambulatory clinics,7 urgent care centers,8 and operating rooms,9^,10 with some yielding positive results in terms of ordering and cost11^,12 and others having no impact.13^,14 Currently, there is little evidence specifically addressing the effect of cost display for medications in the inpatient setting.

As part of an institutional initiative to control pharmaceutical expenditures, informational messaging for several high-cost drugs was initiated at our tertiary care hospital in April 2015. The goal of our study was to assess the effect of these medication cost messages on ordering practices. We hypothesized that the display of inpatient pharmaceutical costs at the time of order entry would result in a reduction in ordering.

Setting, Intervention, and Participants

As part of an effort to educate prescribers about the high cost of medications, 9 intravenous (IV) medications were selected by the Johns Hopkins Hospital Pharmacy and Therapeutics Committee as targets for drug cost messaging. The intention of the committee was to implement a rapid, low-cost, proof-of-concept, quality-improvement project that was not designed as prospective research. Representatives from the pharmacy and clinicians from relevant clinical areas participated in preimplementation discussions to help identify medications that were subjectively felt to be overused at our institution and potentially modifiable through provider education. The criteria for selecting drug targets included a variety of factors, such as medications infrequently ordered but representing a significant cost per dose (eg, eculizumab and ribavirin), frequently ordered medications with less expensive substitutes (eg, linezolid and voriconazole), and high-cost medications without direct therapeutic alternatives (eg, calcitonin). From April 10, 2015, to October 5, 2015, the computerized Provider Order Entry System (cPOE), Sunrise Clinical Manager (Allscripts Corporation, Chicago, IL), displayed the cost for targeted medications. Seven of the medication alerts also included a reasonable therapeutic alternative and its cost. There were no restrictions placed on ordering; prescribers were able to choose the high-cost medications at their discretion.

Despite the fact that this initiative was not designed as a research project, we felt it was important to formally evaluate the impact of the drug cost messaging effort to inform future quality-improvement interventions. Each medication was compared to its preintervention baseline utilization dating back to January 1, 2013. For the 7 medications with alternatives offered, we also analyzed use of the suggested alternative during these time periods.

Data Sources and Measurement

Our study utilized data obtained from the pharmacy order verification system and the cPOE database. Data were collected over a period of 143 weeks from January 1, 2013, to October 5, 2015, to allow for a baseline period (January 1, 2013, to April 9, 2015) and an intervention period (April 10, 2015, to October 5, 2015). Data elements extracted included drug characteristics (dosage form, route, cost, strength, name, and quantity), patient characteristics (race, gender, and age), clinical setting (facility location, inpatient or outpatient), and billing information (provider name, doses dispensed from pharmacy, order number, revenue or procedure code, record number, date of service, and unique billing number) for each admission. Using these elements, we generated the following 8 variables to use in our analyses: week, month, period identifier, drug name, dosage form, weekly orders, weekly patient days, and number of weekly orders per 10,000 patient days. Average wholesale price (AWP), referred to as medication cost in this manuscript, was used to report all drug costs in all associated cost calculations. While the actual cost of acquisition and price charged to the patient may vary based on several factors, including manufacturer and payer, we chose to use AWP as a generalizable estimate of the cost of acquisition of the drug for the hospital.

Variables

“Week” and “month” were defined as the week and month of our study, respectively. The “period identifier” was a binary variable that identified the time period before and after the intervention. “Weekly orders” was defined as the total number of new orders placed per week for each specified drug included in our study. For example, if a patient received 2 discrete, new orders for a medication in a given week, 2 orders would be counted toward the “weekly orders” variable. “Patient days,” defined as the total number of patients treated at our facility, was summated for each week of our study to yield “weekly patient days.” To derive the “number of weekly orders per 10,000 patient days,” we divided weekly orders by weekly patient days and multiplied the resultant figure by 10,000.

Statistical Analysis

Segmented regression, a form of interrupted time series analysis, is a quasi-experimental design that was used to determine the immediate and sustained effects of the drug cost messages on the rate of medication ordering.^15-17 The model enabled the use of comparison groups (alternative medications, as described above) to enhance internal validity.

In time series data, outcomes may not be independent over time. Autocorrelation of the error terms can arise when outcomes are more similar at time points closer together than outcomes at time points further apart. Failure to account for autocorrelation of the error terms may lead to underestimated standard errors. The presence of autocorrelation, assessed by calculating the Durbin-Watson statistic, was significant among our data. To adjust for this, we employed a Prais-Winsten estimation to adjust the error term (ε_t) calculated in our models.

Two segmented linear regression models were used to estimate trends in ordering before and after the intervention. The presence or absence of a comparator drug determined which model was to be used. When only single medications were under study, as in the case of eculizumab and calcitonin, our regression model was as follows:

Y_t = (β₀) + (β₁)(Time_t) + (β₂)(Intervention_t) + (β₃)(Post-Intervention Time_t) + (ε_t)

In our single-drug model, Y_t denoted the number of orders per 10,000 patient days at week “t”; Time_t was a continuous variable that indicated the number of weeks prior to or after the study intervention (April 10, 2015) and ranged from –116 to 27 weeks. Post-Intervention Time_t was a continuous variable that denoted the number of weeks since the start of the intervention and is coded as zero for all time periods prior to the intervention. β₀ was the estimated baseline number of orders per 10,000 patient days at the beginning of the study. β₁ is the trend of orders per 10,000 patient days per week during the preintervention period; β₂ represents an estimate of the change in the number of orders per 10,000 patient days immediately after the intervention; β₃ denotes the difference between preintervention and postintervention slopes; and ε_t is the “error term,” which represents autocorrelation and random variability of the data.

As mentioned previously, alternative dosage forms of 7 medications included in our study were utilized as comparison groups. In these instances (when multiple drugs were included in our analyses), the following regression model was applied:

Y _t = ( β ₀ ) + ( β ₁ )(Time _t ) + ( β ₂ )(Intervention _t ) + ( β ₃ )(Post-Intervention Time _t ) + ( β ₄ )(Cohort) + ( β ₅ )(Cohort)(Time _t ) + ( β ₆ )(Cohort)(Intervention _t ) + ( β ₇ )(Cohort)(Post-Intervention Time _t ) + ( ε _t )

Here, 3 coefficients were added (β₄-β₇) to describe an additional cohort of orders. Cohort, a binary indicator variable, held a value of either 0 or 1 when the model was used to describe the treatment or comparison group, respectively. The coefficients β₄-β₇ described the treatment group, and β₀-β₃ described the comparison group. β₄ was the difference in the number of baseline orders per 10,000 patient days between treatment and comparison groups; Β₅ represented the difference between the estimated ordering trends of treatment and comparison groups; and Β₆ indicated the difference in immediate changes in the number of orders per 10,000 patient days in the 2 groups following the intervention.

The number of orders per week was recorded for each medicine, which enabled a large number of data points to be included in our analyses. This allowed for more accurate and stable estimates to be made in our regression model. A total of 143 data points were collected for each study group, 116 before and 27 following each intervention.

All analyses were conducted by using STATA version 13.1 (StataCorp LP, College Station, TX).

Initial results pertaining to 9 IV medications were examined (Table). Following the implementation of cost messaging, no significant changes were observed in order frequency or trend for IV formulations of eculizumab, calcitonin, levetiracetam, linezolid, mycophenolate, ribavirin, voriconazole, and levothyroxine (Figures 1 and 2). However, a significant decrease in the number of oral ribavirin orders (Figure 2), the control group for the IV form, was observed (–16.3 orders per 10,000 patient days; P = .004; 95% CI, –27.2 to –5.31).

Our results suggest that the passive strategy of displaying cost alone was not effective in altering prescriber ordering patterns for the selected medications. This may be due to a lack of awareness regarding direct financial impact on the patient, importance of costs in medical decision-making, or a perceived lack of alternatives or suitability of recommended alternatives. These results may prove valuable to hospital and pharmacy leadership as they develop strategies to curb medication expense.

Changes observed in IV pantoprazole ordering are instructive. Due to a national shortage, the IV form of this medication underwent a restriction, which required approval by the pharmacy prior to dispensing. This restriction was instituted independently of our study and led to a 73% decrease from usage rates prior to policy implementation (Figure 3). Ordering was restricted according to defined criteria for IV use. The restriction did not apply to oral pantoprazole, and no significant change in ordering of the oral formulation was noted during the evaluated period (Figure 3).

Disclosures: The authors state that there were no external sponsors for this work. The Johns Hopkins Hospital and University “funded” this work by paying the salaries of the authors. The author team maintained independence and made all decisions regarding the study design, data collection, data analysis, interpretation of results, writing of the research report, and decision to submit it for publication. Dr. Shermock had full access to all the study data and takes responsibility for the integrity of the data and accuracy of the data analysis.

Secondary to rising healthcare costs in the United States, broad efforts are underway to identify and reduce waste in the health system.1,2 A recent systematic review exhibited that many physicians inaccurately estimate the cost of medications.3 Raising awareness of medication costs among prescribers is one potential way to promote high-value care.

Some evidence suggests that cost transparency may help prescribers understand how medication orders drive costs. In a previous study carried out at the Johns Hopkins Hospital, fee data were displayed to providers for diagnostic laboratory tests.4 An 8.6% decrease (95% confidence interval [CI], –8.99% to –8.19%) in test ordering was observed when costs were displayed vs a 5.6% increase (95% CI, 4.90% to 6.39%) in ordering when costs were not displayed during a 6-month intervention period (P < 0.001). Conversely, a similar study that investigated the impact of cost transparency on inpatient imaging utilization did not demonstrate a significant influence of cost display.5 This suggests that cost transparency may work in some areas of care but not in others. A systematic review that investigated price-display interventions for imaging, laboratory studies, and medications reported 10 studies that demonstrated a statistically significant decrease in expenditures without an effect on patient safety.6

Informing prescribers of institution-specific medication costs within and between drug classes may enable the selection of less expensive, therapeutically equivalent drugs. Prior studies investigating the effect of medication cost display were conducted in a variety of patient care settings, including ambulatory clinics,7 urgent care centers,8 and operating rooms,9^,10 with some yielding positive results in terms of ordering and cost11^,12 and others having no impact.13^,14 Currently, there is little evidence specifically addressing the effect of cost display for medications in the inpatient setting.

As part of an institutional initiative to control pharmaceutical expenditures, informational messaging for several high-cost drugs was initiated at our tertiary care hospital in April 2015. The goal of our study was to assess the effect of these medication cost messages on ordering practices. We hypothesized that the display of inpatient pharmaceutical costs at the time of order entry would result in a reduction in ordering.

Setting, Intervention, and Participants

As part of an effort to educate prescribers about the high cost of medications, 9 intravenous (IV) medications were selected by the Johns Hopkins Hospital Pharmacy and Therapeutics Committee as targets for drug cost messaging. The intention of the committee was to implement a rapid, low-cost, proof-of-concept, quality-improvement project that was not designed as prospective research. Representatives from the pharmacy and clinicians from relevant clinical areas participated in preimplementation discussions to help identify medications that were subjectively felt to be overused at our institution and potentially modifiable through provider education. The criteria for selecting drug targets included a variety of factors, such as medications infrequently ordered but representing a significant cost per dose (eg, eculizumab and ribavirin), frequently ordered medications with less expensive substitutes (eg, linezolid and voriconazole), and high-cost medications without direct therapeutic alternatives (eg, calcitonin). From April 10, 2015, to October 5, 2015, the computerized Provider Order Entry System (cPOE), Sunrise Clinical Manager (Allscripts Corporation, Chicago, IL), displayed the cost for targeted medications. Seven of the medication alerts also included a reasonable therapeutic alternative and its cost. There were no restrictions placed on ordering; prescribers were able to choose the high-cost medications at their discretion.

Despite the fact that this initiative was not designed as a research project, we felt it was important to formally evaluate the impact of the drug cost messaging effort to inform future quality-improvement interventions. Each medication was compared to its preintervention baseline utilization dating back to January 1, 2013. For the 7 medications with alternatives offered, we also analyzed use of the suggested alternative during these time periods.

Data Sources and Measurement

Our study utilized data obtained from the pharmacy order verification system and the cPOE database. Data were collected over a period of 143 weeks from January 1, 2013, to October 5, 2015, to allow for a baseline period (January 1, 2013, to April 9, 2015) and an intervention period (April 10, 2015, to October 5, 2015). Data elements extracted included drug characteristics (dosage form, route, cost, strength, name, and quantity), patient characteristics (race, gender, and age), clinical setting (facility location, inpatient or outpatient), and billing information (provider name, doses dispensed from pharmacy, order number, revenue or procedure code, record number, date of service, and unique billing number) for each admission. Using these elements, we generated the following 8 variables to use in our analyses: week, month, period identifier, drug name, dosage form, weekly orders, weekly patient days, and number of weekly orders per 10,000 patient days. Average wholesale price (AWP), referred to as medication cost in this manuscript, was used to report all drug costs in all associated cost calculations. While the actual cost of acquisition and price charged to the patient may vary based on several factors, including manufacturer and payer, we chose to use AWP as a generalizable estimate of the cost of acquisition of the drug for the hospital.

Variables

“Week” and “month” were defined as the week and month of our study, respectively. The “period identifier” was a binary variable that identified the time period before and after the intervention. “Weekly orders” was defined as the total number of new orders placed per week for each specified drug included in our study. For example, if a patient received 2 discrete, new orders for a medication in a given week, 2 orders would be counted toward the “weekly orders” variable. “Patient days,” defined as the total number of patients treated at our facility, was summated for each week of our study to yield “weekly patient days.” To derive the “number of weekly orders per 10,000 patient days,” we divided weekly orders by weekly patient days and multiplied the resultant figure by 10,000.

Statistical Analysis

Segmented regression, a form of interrupted time series analysis, is a quasi-experimental design that was used to determine the immediate and sustained effects of the drug cost messages on the rate of medication ordering.^15-17 The model enabled the use of comparison groups (alternative medications, as described above) to enhance internal validity.

In time series data, outcomes may not be independent over time. Autocorrelation of the error terms can arise when outcomes are more similar at time points closer together than outcomes at time points further apart. Failure to account for autocorrelation of the error terms may lead to underestimated standard errors. The presence of autocorrelation, assessed by calculating the Durbin-Watson statistic, was significant among our data. To adjust for this, we employed a Prais-Winsten estimation to adjust the error term (ε_t) calculated in our models.

Two segmented linear regression models were used to estimate trends in ordering before and after the intervention. The presence or absence of a comparator drug determined which model was to be used. When only single medications were under study, as in the case of eculizumab and calcitonin, our regression model was as follows:

Y_t = (β₀) + (β₁)(Time_t) + (β₂)(Intervention_t) + (β₃)(Post-Intervention Time_t) + (ε_t)

In our single-drug model, Y_t denoted the number of orders per 10,000 patient days at week “t”; Time_t was a continuous variable that indicated the number of weeks prior to or after the study intervention (April 10, 2015) and ranged from –116 to 27 weeks. Post-Intervention Time_t was a continuous variable that denoted the number of weeks since the start of the intervention and is coded as zero for all time periods prior to the intervention. β₀ was the estimated baseline number of orders per 10,000 patient days at the beginning of the study. β₁ is the trend of orders per 10,000 patient days per week during the preintervention period; β₂ represents an estimate of the change in the number of orders per 10,000 patient days immediately after the intervention; β₃ denotes the difference between preintervention and postintervention slopes; and ε_t is the “error term,” which represents autocorrelation and random variability of the data.

As mentioned previously, alternative dosage forms of 7 medications included in our study were utilized as comparison groups. In these instances (when multiple drugs were included in our analyses), the following regression model was applied:

Y _t = ( β ₀ ) + ( β ₁ )(Time _t ) + ( β ₂ )(Intervention _t ) + ( β ₃ )(Post-Intervention Time _t ) + ( β ₄ )(Cohort) + ( β ₅ )(Cohort)(Time _t ) + ( β ₆ )(Cohort)(Intervention _t ) + ( β ₇ )(Cohort)(Post-Intervention Time _t ) + ( ε _t )

Here, 3 coefficients were added (β₄-β₇) to describe an additional cohort of orders. Cohort, a binary indicator variable, held a value of either 0 or 1 when the model was used to describe the treatment or comparison group, respectively. The coefficients β₄-β₇ described the treatment group, and β₀-β₃ described the comparison group. β₄ was the difference in the number of baseline orders per 10,000 patient days between treatment and comparison groups; Β₅ represented the difference between the estimated ordering trends of treatment and comparison groups; and Β₆ indicated the difference in immediate changes in the number of orders per 10,000 patient days in the 2 groups following the intervention.

The number of orders per week was recorded for each medicine, which enabled a large number of data points to be included in our analyses. This allowed for more accurate and stable estimates to be made in our regression model. A total of 143 data points were collected for each study group, 116 before and 27 following each intervention.

All analyses were conducted by using STATA version 13.1 (StataCorp LP, College Station, TX).

Initial results pertaining to 9 IV medications were examined (Table). Following the implementation of cost messaging, no significant changes were observed in order frequency or trend for IV formulations of eculizumab, calcitonin, levetiracetam, linezolid, mycophenolate, ribavirin, voriconazole, and levothyroxine (Figures 1 and 2). However, a significant decrease in the number of oral ribavirin orders (Figure 2), the control group for the IV form, was observed (–16.3 orders per 10,000 patient days; P = .004; 95% CI, –27.2 to –5.31).

Our results suggest that the passive strategy of displaying cost alone was not effective in altering prescriber ordering patterns for the selected medications. This may be due to a lack of awareness regarding direct financial impact on the patient, importance of costs in medical decision-making, or a perceived lack of alternatives or suitability of recommended alternatives. These results may prove valuable to hospital and pharmacy leadership as they develop strategies to curb medication expense.

Changes observed in IV pantoprazole ordering are instructive. Due to a national shortage, the IV form of this medication underwent a restriction, which required approval by the pharmacy prior to dispensing. This restriction was instituted independently of our study and led to a 73% decrease from usage rates prior to policy implementation (Figure 3). Ordering was restricted according to defined criteria for IV use. The restriction did not apply to oral pantoprazole, and no significant change in ordering of the oral formulation was noted during the evaluated period (Figure 3).

Disclosures: The authors state that there were no external sponsors for this work. The Johns Hopkins Hospital and University “funded” this work by paying the salaries of the authors. The author team maintained independence and made all decisions regarding the study design, data collection, data analysis, interpretation of results, writing of the research report, and decision to submit it for publication. Dr. Shermock had full access to all the study data and takes responsibility for the integrity of the data and accuracy of the data analysis.

The “Things We Do for No Reason” (TWDFNR) series reviews practices which have become common parts of hospital care but which may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent “black and white” conclusions or clinical practice standards, but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion. https://www.choosingwisely.org/

Hospitals and health systems worldwide have adopted policies for routine replacement of peripheral intravenous catheters (PIVCs) at prespecified time intervals (range, 48-96 hours). This practice accounts for a large number of PIVC reinsertions and places a significant cost burden on the healthcare infrastructure. The authors of this article examine the evidence that has been used to support this practice.

CASE PRESENTATION

A 67-year-old man with metastatic lung cancer presents to a hospital for pain control and “failure to thrive.” In the emergency department, a left antecubital peripheral intravenous catheter (PIVC) is placed. On admission, a prerenal acute kidney injury is noted. During the patient’s entire hospitalization, normal saline with parenteral hydromorphone is administered. On hospital day 4, the pain is still not adequately controlled, and the intravenous opioid is continued. On morning rounds, an intern notes that the PIVC is functioning well, and there are no signs of irritation. However, the nursing staff reminds the team that the PIVC should be changed because it has been in place for 4 days and is “due for replacement.” The patient does not want to receive another skin puncture for routine venous access. Does the PIVC need to be replaced, per routine?

WHY YOU MIGHT THINK ROUTINE PIVC REPLACEMENT IS HELPFUL

PIVC placement is easily the most common procedure performed in the United States. An estimated 200 million PIVCs are placed each year.¹ Given the number of inpatient hospital stays per year in the United States alone—more than 37 million^1,2—data regarding the care, maintenance, and complications of PIVCs are essential to the healthcare infrastructure. 

The recommendation to routinely replace PIVCs dates to 1981, when the Centers for Disease Control and Prevention³ (CDC) issued a guideline that calls for replacing PIVCs every 24 to 48 hours. Most of the data and studies that established that recommendation originated in the 1970s, when catheters varied in length and material, and precise definitions of complications, such as phlebitis—localized vein inflammation characterized by pain, erythema, tenderness, swelling, and a palpable cord^4,5—were not standardized across trials. Research at the time suggested higher rates of complications from IVCs dwelling longer than 48 to 72 hours. The latest (2011) CDC guidelines^6,7 softened the recommendation but still concluded, “There is no need to replace peripheral catheters more frequently than every 72-96 hours.”

The 2011 recommendation^6,7 is based on findings of a 1983 prospective observational study,⁸ a 1991 randomized controlled trial (RCT),⁹ and a 1998 prospective observational study.² The 1983 and 1991 studies found higher rates of PIVC complications after day 2 of cannulation.^8,9 The 1998 study found no increase in the rate of complications after day 3 of catheterization, and its authors, recommending a reevaluation of the need to routinely replace PIVCs, wrote, “[The] hazard for catheter-related complications, phlebitis, catheter-related infections, and mechanical complications did not increase during prolonged catheterization.”²

Results of RCTs conducted by Barker et al.¹⁰ (2004) and Nishanth et al.¹¹ (2009) supported the claim that routine replacement of PIVCs leads to lower rates of thrombophlebitis. Nishanth et al. also included site pain and cannula dislodgement in their definition of phlebitis. Neither study compared blood stream infection rates, but both found higher rates of phlebitis between day 2.5 and day 3. However, Cochrane reviewers Webster et al.¹² questioned the findings of these 2 trials, given their missing data and possibly biased results and conclusions. In the Barker study, patient numbers (screened, eligible, dropout) were unclear; each patient group was unbalanced; protocol deviations were not reported (possibly a result of incomplete data reporting or inappropriate randomization); and varied definitions of phlebitis were allowed, which may have resulted in more events being included. In the Nishanth study, the 100% phlebitis rate for the clinically indicated replacement group seemed extreme, which suggested confounding by an unknown bias or chance. Last, both samples were small: 47 patients (Barker) and 42 patients (Nishanth). Given all these concerns, the 2 trials were excluded from the Cochrane meta-analysis on the subject.¹²

In the 1980s and early 1990s, routine removal and exchange of PIVCs were supported by limited evidence. Current well-designed trial data cast doubt on the need for such a practice.

WHY YOU SHOULD NOT ROUTINELY REPLACE PIVCs

According to the CDC,^6,7 the issue of routine PIVC replacement remains unresolved: “No recommendation is made regarding replacement of peripheral catheters in adults only when clinically indicated.”

Whereas earlier data showed a higher risk of complications with longer dwelling IVs, the majority of contemporary data has failed to support this conclusion. The recent (2015) Cochrane meta-analysis comparing routine with clinically indicated IVC replacement found “no evidence to support changing catheters every 72-96 hours.”¹² Of the 7 studies that fulfilled the criteria for qualitative analysis, only 5 were included (the studies by Barker et al.¹⁰ and Nishanth et al.¹¹ were excluded). The included studies assessed the endpoints of catheter-related blood stream infection (CRBSI), phlebitis, phlebitis per device-days, mortality, cost, and infiltration. Statistically significant differences were found only for cost (favoring clinically indicated replacement) and infiltration (occurring less with routine replacement). 

The largest and most robust RCT in the meta-analysis¹² was conducted by Rickard et al.¹³ (2012). Their nonblinded, intention-to-treat study of 3283 patients used concealed allocation to randomly assign patients to either clinically indicated or routine PIVC replacement in order to evaluate a primary endpoint, phlebitis. Secondary endpoints were CRBSI, venous port infection, IVC tip colonization, infusion failure, number of IVCs needed per patient, IV therapy duration, cost, and mortality. Need for PIVC replacement was methodically monitored (Table) with extensive nursing education and interrater validation. The study found no difference in the groups’ phlebitis rates; the rate was 7% for both routine and clinically indicated replacement (13.08% and 13.11%, respectively, adjusted for phlebitis per 1000 IVC days). In addition, there was no difference in the secondary outcome measures, except cost and number of catheters used, both of which favored clinically indicated replacement. The most serious complication, CRBSI, occurred at essentially the same rate in the 2 replacement arms: 0.11% (routine) and 0% (clinically indicated). Per-patient cost for the entire course of treatment was A$69.24 in the routine group and A$61.66 in the clinically indicated group; the difference was A$7.58 (P < 0.0001). Mean number of catheters used was 1.9 in the routine group and 1.7 in the clinically indicated group; the difference was 0.21 catheter per patient for the treatment course (P < 0.0001). Overall, the study found no important difference in significant outcomes between the 2 study arms.

The other 4 studies in the meta-analysis¹² duplicated these results, with none finding a higher rate of major adverse events.^14-17 All 4 showed virtually equivalent rates of phlebitis, the primary outcome; 3 also examined the secondary outcome measure of blood stream infection, and results were similar, with identical rates of complications. Only 1 trial identified any bloodstream infections (1 per group).¹⁵ The meta-analysis did find that routine catheter replacement resulted in less catheter infiltration. 

Most of the data on PIVC exchange involves phlebitis and other local complications. A prospective study by Stuart et al.¹⁸ and commentary by Collignon et al.¹⁹ underscore the need for further research targeting blood stream infections (sepsis and severe sepsis in particular) as a primary outcome. Blood stream infections, especially those related to PIVC use, are rare entities overall, with most recent data yielding an estimated rate of 0.5 per 1000 catheter-days.²⁰ Given this epidemiologic finding, researchers trying to acquire meaningful data on PIVC-related blood stream infections and subsequent complications would need to have tens of thousands of patients in routine and clinically indicated replacement arms to sufficiently power their studies.²⁰ As they are infeasible, such trials cannot be found in the scientific literature.

Stuart et al.¹⁸ tried addressing the question. Prospectively examining more than 5 million occupied-bed days and the incidence of bloodstream infections by type of intravascular device over a 5-year period, they found that 137 (23.5%) of 583 healthcare-associated Staphylococcus aureus bacteremia (SAB) cases were attributed to PIVC use. PIVC insertions were performed equally (39.6%) in emergency departments and medical wards. About 45% of PIVCs remained in place 4 days or longer. Stuart et al. noted the “significant issue of PIVC-associated SAB” and favored routine removal of PIVCs within 96 hours (4 days). However, 55% of patients in their PIVC-related SAB group had the device in place less than 4 days. In addition, overall incidence of SAB was low: 0.3 per 10,000 occupied-bed days. Further, their study did not adjust device-specific SAB incidence for frequency of device use. For example, the rate of healthcare-acquired SAB was 19.7% for central venous catheters and 23.5% for PIVCs, despite PIVCs being used significantly more often than central lines. Device-specific adjustments would show a vastly different absolute risk of SAB in relation to individual devices. Nevertheless, the overall benefit of and need for routine PIVC replacement must be questioned. The percentage of PIVC-associated SAB in their study and the need for more research in this area should be noted. Given current information, their study and others in the literature underscore the need for selective use, appropriate maintenance, and timely removal of PIVCs.

Pure clinical outcomes are important, but procedural costs are as well. Clinically indicated replacement helps patients avoid an unpleasant procedure and saves money.²¹ If one third of the 37 million annual inpatient admissions require a PIVC for more than 3 days, then a strategy of “replacement when clinically indicated” could prevent almost 2.5 million unnecessary PIVC insertions each year. Equipment cost savings combined with savings of nearly 1 million staff hours could yield an estimated $400 million in savings over a 5-year period.²² Given current data suggesting no harm from clinically indicated PIVC replacement and clear evidence that routine replacement increases needle sticks and costs, it seems time to end the practice of routine PIVC replacement.

Compared with clinically indicated catheter replacement, routine replacement in the absence of a clinical indication (eg, infiltration, phlebitis, infection) provides no added benefit. Studies have consistently found that rates of phlebitis and SAB are not affected by scheduled replacement, though the largest RCT may not have been powered to show a difference in SAB. The present authors’ recommendations for PIVC care are:

• Scrutinize each patient’s need for PIVCs and remove each PIVC as soon as possible.
• Do not make routine replacement of otherwise well-functioning, well-appearing clinically necessary PIVCs the standard of care.
• Regularly examine PIVC sites for signs and symptoms of infection.
• Remove a PIVC immediately on recognition of any clinical sign of a complication (eg, infiltration, phlebitis, localized infection, blood stream infection) and replace the PIVC only if there is a clinical need.
• If replacing PIVCs on a clinical basis, establish protocols for frequency of evaluation for complications; these protocols might mirror those from prior studies (Table).^10,22
• Replace as soon as possible any PIVC inserted during an urgent or emergent situation in which proper insertion technique could not be guaranteed.
• Conduct real-world observational studies to ensure that the switch to clinically driven replacement is safe and develop standardized definitions of complications.

Given the literature findings and the preceding recommendations, the authors conclude that the patient in the case example does not need routine PIVC replacement. His PIVC may remain in place as long as evaluation for local complications is routinely and methodically performed and the device is removed as soon as it is deemed unnecessary (transition to oral opioid therapy).

The long-standing practice of routinely replacing PIVCs every 72 to 96 hours during a hospital stay does not affect any meaningful clinical outcome. Specifically, data do not show that routine replacement prevents phlebitis or blood stream infections. Furthermore, routine PIVC replacement increases patient discomfort, uses resources unnecessarily, and raises hospital costs. Most of the PIVC research has involved phlebitis and other local complications; more research on PIVC use and bloodstream infections is needed. Given the findings in the current literature, routine PIVC replacement should be considered a Thing We Do For No Reason.

Disclosure

Nothing to report. 

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason”? Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason” topics by emailing TWDFNR@hospitalmedicine.org.

The “Things We Do for No Reason” (TWDFNR) series reviews practices which have become common parts of hospital care but which may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent “black and white” conclusions or clinical practice standards, but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion. https://www.choosingwisely.org/

Hospitals and health systems worldwide have adopted policies for routine replacement of peripheral intravenous catheters (PIVCs) at prespecified time intervals (range, 48-96 hours). This practice accounts for a large number of PIVC reinsertions and places a significant cost burden on the healthcare infrastructure. The authors of this article examine the evidence that has been used to support this practice.

CASE PRESENTATION

A 67-year-old man with metastatic lung cancer presents to a hospital for pain control and “failure to thrive.” In the emergency department, a left antecubital peripheral intravenous catheter (PIVC) is placed. On admission, a prerenal acute kidney injury is noted. During the patient’s entire hospitalization, normal saline with parenteral hydromorphone is administered. On hospital day 4, the pain is still not adequately controlled, and the intravenous opioid is continued. On morning rounds, an intern notes that the PIVC is functioning well, and there are no signs of irritation. However, the nursing staff reminds the team that the PIVC should be changed because it has been in place for 4 days and is “due for replacement.” The patient does not want to receive another skin puncture for routine venous access. Does the PIVC need to be replaced, per routine?

WHY YOU MIGHT THINK ROUTINE PIVC REPLACEMENT IS HELPFUL

PIVC placement is easily the most common procedure performed in the United States. An estimated 200 million PIVCs are placed each year.¹ Given the number of inpatient hospital stays per year in the United States alone—more than 37 million^1,2—data regarding the care, maintenance, and complications of PIVCs are essential to the healthcare infrastructure. 

The recommendation to routinely replace PIVCs dates to 1981, when the Centers for Disease Control and Prevention³ (CDC) issued a guideline that calls for replacing PIVCs every 24 to 48 hours. Most of the data and studies that established that recommendation originated in the 1970s, when catheters varied in length and material, and precise definitions of complications, such as phlebitis—localized vein inflammation characterized by pain, erythema, tenderness, swelling, and a palpable cord^4,5—were not standardized across trials. Research at the time suggested higher rates of complications from IVCs dwelling longer than 48 to 72 hours. The latest (2011) CDC guidelines^6,7 softened the recommendation but still concluded, “There is no need to replace peripheral catheters more frequently than every 72-96 hours.”

The 2011 recommendation^6,7 is based on findings of a 1983 prospective observational study,⁸ a 1991 randomized controlled trial (RCT),⁹ and a 1998 prospective observational study.² The 1983 and 1991 studies found higher rates of PIVC complications after day 2 of cannulation.^8,9 The 1998 study found no increase in the rate of complications after day 3 of catheterization, and its authors, recommending a reevaluation of the need to routinely replace PIVCs, wrote, “[The] hazard for catheter-related complications, phlebitis, catheter-related infections, and mechanical complications did not increase during prolonged catheterization.”²

Results of RCTs conducted by Barker et al.¹⁰ (2004) and Nishanth et al.¹¹ (2009) supported the claim that routine replacement of PIVCs leads to lower rates of thrombophlebitis. Nishanth et al. also included site pain and cannula dislodgement in their definition of phlebitis. Neither study compared blood stream infection rates, but both found higher rates of phlebitis between day 2.5 and day 3. However, Cochrane reviewers Webster et al.¹² questioned the findings of these 2 trials, given their missing data and possibly biased results and conclusions. In the Barker study, patient numbers (screened, eligible, dropout) were unclear; each patient group was unbalanced; protocol deviations were not reported (possibly a result of incomplete data reporting or inappropriate randomization); and varied definitions of phlebitis were allowed, which may have resulted in more events being included. In the Nishanth study, the 100% phlebitis rate for the clinically indicated replacement group seemed extreme, which suggested confounding by an unknown bias or chance. Last, both samples were small: 47 patients (Barker) and 42 patients (Nishanth). Given all these concerns, the 2 trials were excluded from the Cochrane meta-analysis on the subject.¹²

In the 1980s and early 1990s, routine removal and exchange of PIVCs were supported by limited evidence. Current well-designed trial data cast doubt on the need for such a practice.

WHY YOU SHOULD NOT ROUTINELY REPLACE PIVCs

According to the CDC,^6,7 the issue of routine PIVC replacement remains unresolved: “No recommendation is made regarding replacement of peripheral catheters in adults only when clinically indicated.”

Whereas earlier data showed a higher risk of complications with longer dwelling IVs, the majority of contemporary data has failed to support this conclusion. The recent (2015) Cochrane meta-analysis comparing routine with clinically indicated IVC replacement found “no evidence to support changing catheters every 72-96 hours.”¹² Of the 7 studies that fulfilled the criteria for qualitative analysis, only 5 were included (the studies by Barker et al.¹⁰ and Nishanth et al.¹¹ were excluded). The included studies assessed the endpoints of catheter-related blood stream infection (CRBSI), phlebitis, phlebitis per device-days, mortality, cost, and infiltration. Statistically significant differences were found only for cost (favoring clinically indicated replacement) and infiltration (occurring less with routine replacement). 

The largest and most robust RCT in the meta-analysis¹² was conducted by Rickard et al.¹³ (2012). Their nonblinded, intention-to-treat study of 3283 patients used concealed allocation to randomly assign patients to either clinically indicated or routine PIVC replacement in order to evaluate a primary endpoint, phlebitis. Secondary endpoints were CRBSI, venous port infection, IVC tip colonization, infusion failure, number of IVCs needed per patient, IV therapy duration, cost, and mortality. Need for PIVC replacement was methodically monitored (Table) with extensive nursing education and interrater validation. The study found no difference in the groups’ phlebitis rates; the rate was 7% for both routine and clinically indicated replacement (13.08% and 13.11%, respectively, adjusted for phlebitis per 1000 IVC days). In addition, there was no difference in the secondary outcome measures, except cost and number of catheters used, both of which favored clinically indicated replacement. The most serious complication, CRBSI, occurred at essentially the same rate in the 2 replacement arms: 0.11% (routine) and 0% (clinically indicated). Per-patient cost for the entire course of treatment was A$69.24 in the routine group and A$61.66 in the clinically indicated group; the difference was A$7.58 (P < 0.0001). Mean number of catheters used was 1.9 in the routine group and 1.7 in the clinically indicated group; the difference was 0.21 catheter per patient for the treatment course (P < 0.0001). Overall, the study found no important difference in significant outcomes between the 2 study arms.

The other 4 studies in the meta-analysis¹² duplicated these results, with none finding a higher rate of major adverse events.^14-17 All 4 showed virtually equivalent rates of phlebitis, the primary outcome; 3 also examined the secondary outcome measure of blood stream infection, and results were similar, with identical rates of complications. Only 1 trial identified any bloodstream infections (1 per group).¹⁵ The meta-analysis did find that routine catheter replacement resulted in less catheter infiltration. 

Most of the data on PIVC exchange involves phlebitis and other local complications. A prospective study by Stuart et al.¹⁸ and commentary by Collignon et al.¹⁹ underscore the need for further research targeting blood stream infections (sepsis and severe sepsis in particular) as a primary outcome. Blood stream infections, especially those related to PIVC use, are rare entities overall, with most recent data yielding an estimated rate of 0.5 per 1000 catheter-days.²⁰ Given this epidemiologic finding, researchers trying to acquire meaningful data on PIVC-related blood stream infections and subsequent complications would need to have tens of thousands of patients in routine and clinically indicated replacement arms to sufficiently power their studies.²⁰ As they are infeasible, such trials cannot be found in the scientific literature.

Stuart et al.¹⁸ tried addressing the question. Prospectively examining more than 5 million occupied-bed days and the incidence of bloodstream infections by type of intravascular device over a 5-year period, they found that 137 (23.5%) of 583 healthcare-associated Staphylococcus aureus bacteremia (SAB) cases were attributed to PIVC use. PIVC insertions were performed equally (39.6%) in emergency departments and medical wards. About 45% of PIVCs remained in place 4 days or longer. Stuart et al. noted the “significant issue of PIVC-associated SAB” and favored routine removal of PIVCs within 96 hours (4 days). However, 55% of patients in their PIVC-related SAB group had the device in place less than 4 days. In addition, overall incidence of SAB was low: 0.3 per 10,000 occupied-bed days. Further, their study did not adjust device-specific SAB incidence for frequency of device use. For example, the rate of healthcare-acquired SAB was 19.7% for central venous catheters and 23.5% for PIVCs, despite PIVCs being used significantly more often than central lines. Device-specific adjustments would show a vastly different absolute risk of SAB in relation to individual devices. Nevertheless, the overall benefit of and need for routine PIVC replacement must be questioned. The percentage of PIVC-associated SAB in their study and the need for more research in this area should be noted. Given current information, their study and others in the literature underscore the need for selective use, appropriate maintenance, and timely removal of PIVCs.

Pure clinical outcomes are important, but procedural costs are as well. Clinically indicated replacement helps patients avoid an unpleasant procedure and saves money.²¹ If one third of the 37 million annual inpatient admissions require a PIVC for more than 3 days, then a strategy of “replacement when clinically indicated” could prevent almost 2.5 million unnecessary PIVC insertions each year. Equipment cost savings combined with savings of nearly 1 million staff hours could yield an estimated $400 million in savings over a 5-year period.²² Given current data suggesting no harm from clinically indicated PIVC replacement and clear evidence that routine replacement increases needle sticks and costs, it seems time to end the practice of routine PIVC replacement.

Compared with clinically indicated catheter replacement, routine replacement in the absence of a clinical indication (eg, infiltration, phlebitis, infection) provides no added benefit. Studies have consistently found that rates of phlebitis and SAB are not affected by scheduled replacement, though the largest RCT may not have been powered to show a difference in SAB. The present authors’ recommendations for PIVC care are:

• Scrutinize each patient’s need for PIVCs and remove each PIVC as soon as possible.
• Do not make routine replacement of otherwise well-functioning, well-appearing clinically necessary PIVCs the standard of care.
• Regularly examine PIVC sites for signs and symptoms of infection.
• Remove a PIVC immediately on recognition of any clinical sign of a complication (eg, infiltration, phlebitis, localized infection, blood stream infection) and replace the PIVC only if there is a clinical need.
• If replacing PIVCs on a clinical basis, establish protocols for frequency of evaluation for complications; these protocols might mirror those from prior studies (Table).^10,22
• Replace as soon as possible any PIVC inserted during an urgent or emergent situation in which proper insertion technique could not be guaranteed.
• Conduct real-world observational studies to ensure that the switch to clinically driven replacement is safe and develop standardized definitions of complications.

Given the literature findings and the preceding recommendations, the authors conclude that the patient in the case example does not need routine PIVC replacement. His PIVC may remain in place as long as evaluation for local complications is routinely and methodically performed and the device is removed as soon as it is deemed unnecessary (transition to oral opioid therapy).

The long-standing practice of routinely replacing PIVCs every 72 to 96 hours during a hospital stay does not affect any meaningful clinical outcome. Specifically, data do not show that routine replacement prevents phlebitis or blood stream infections. Furthermore, routine PIVC replacement increases patient discomfort, uses resources unnecessarily, and raises hospital costs. Most of the PIVC research has involved phlebitis and other local complications; more research on PIVC use and bloodstream infections is needed. Given the findings in the current literature, routine PIVC replacement should be considered a Thing We Do For No Reason.

Disclosure

Nothing to report. 

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason”? Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason” topics by emailing TWDFNR@hospitalmedicine.org.

The “Things We Do for No Reason” (TWDFNR) series reviews practices which have become common parts of hospital care but which may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent “black and white” conclusions or clinical practice standards, but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion. https://www.choosingwisely.org/

Hospitals and health systems worldwide have adopted policies for routine replacement of peripheral intravenous catheters (PIVCs) at prespecified time intervals (range, 48-96 hours). This practice accounts for a large number of PIVC reinsertions and places a significant cost burden on the healthcare infrastructure. The authors of this article examine the evidence that has been used to support this practice.

CASE PRESENTATION

A 67-year-old man with metastatic lung cancer presents to a hospital for pain control and “failure to thrive.” In the emergency department, a left antecubital peripheral intravenous catheter (PIVC) is placed. On admission, a prerenal acute kidney injury is noted. During the patient’s entire hospitalization, normal saline with parenteral hydromorphone is administered. On hospital day 4, the pain is still not adequately controlled, and the intravenous opioid is continued. On morning rounds, an intern notes that the PIVC is functioning well, and there are no signs of irritation. However, the nursing staff reminds the team that the PIVC should be changed because it has been in place for 4 days and is “due for replacement.” The patient does not want to receive another skin puncture for routine venous access. Does the PIVC need to be replaced, per routine?

WHY YOU MIGHT THINK ROUTINE PIVC REPLACEMENT IS HELPFUL

PIVC placement is easily the most common procedure performed in the United States. An estimated 200 million PIVCs are placed each year.¹ Given the number of inpatient hospital stays per year in the United States alone—more than 37 million^1,2—data regarding the care, maintenance, and complications of PIVCs are essential to the healthcare infrastructure. 

The recommendation to routinely replace PIVCs dates to 1981, when the Centers for Disease Control and Prevention³ (CDC) issued a guideline that calls for replacing PIVCs every 24 to 48 hours. Most of the data and studies that established that recommendation originated in the 1970s, when catheters varied in length and material, and precise definitions of complications, such as phlebitis—localized vein inflammation characterized by pain, erythema, tenderness, swelling, and a palpable cord^4,5—were not standardized across trials. Research at the time suggested higher rates of complications from IVCs dwelling longer than 48 to 72 hours. The latest (2011) CDC guidelines^6,7 softened the recommendation but still concluded, “There is no need to replace peripheral catheters more frequently than every 72-96 hours.”

The 2011 recommendation^6,7 is based on findings of a 1983 prospective observational study,⁸ a 1991 randomized controlled trial (RCT),⁹ and a 1998 prospective observational study.² The 1983 and 1991 studies found higher rates of PIVC complications after day 2 of cannulation.^8,9 The 1998 study found no increase in the rate of complications after day 3 of catheterization, and its authors, recommending a reevaluation of the need to routinely replace PIVCs, wrote, “[The] hazard for catheter-related complications, phlebitis, catheter-related infections, and mechanical complications did not increase during prolonged catheterization.”²

Results of RCTs conducted by Barker et al.¹⁰ (2004) and Nishanth et al.¹¹ (2009) supported the claim that routine replacement of PIVCs leads to lower rates of thrombophlebitis. Nishanth et al. also included site pain and cannula dislodgement in their definition of phlebitis. Neither study compared blood stream infection rates, but both found higher rates of phlebitis between day 2.5 and day 3. However, Cochrane reviewers Webster et al.¹² questioned the findings of these 2 trials, given their missing data and possibly biased results and conclusions. In the Barker study, patient numbers (screened, eligible, dropout) were unclear; each patient group was unbalanced; protocol deviations were not reported (possibly a result of incomplete data reporting or inappropriate randomization); and varied definitions of phlebitis were allowed, which may have resulted in more events being included. In the Nishanth study, the 100% phlebitis rate for the clinically indicated replacement group seemed extreme, which suggested confounding by an unknown bias or chance. Last, both samples were small: 47 patients (Barker) and 42 patients (Nishanth). Given all these concerns, the 2 trials were excluded from the Cochrane meta-analysis on the subject.¹²

In the 1980s and early 1990s, routine removal and exchange of PIVCs were supported by limited evidence. Current well-designed trial data cast doubt on the need for such a practice.

WHY YOU SHOULD NOT ROUTINELY REPLACE PIVCs

According to the CDC,^6,7 the issue of routine PIVC replacement remains unresolved: “No recommendation is made regarding replacement of peripheral catheters in adults only when clinically indicated.”

Whereas earlier data showed a higher risk of complications with longer dwelling IVs, the majority of contemporary data has failed to support this conclusion. The recent (2015) Cochrane meta-analysis comparing routine with clinically indicated IVC replacement found “no evidence to support changing catheters every 72-96 hours.”¹² Of the 7 studies that fulfilled the criteria for qualitative analysis, only 5 were included (the studies by Barker et al.¹⁰ and Nishanth et al.¹¹ were excluded). The included studies assessed the endpoints of catheter-related blood stream infection (CRBSI), phlebitis, phlebitis per device-days, mortality, cost, and infiltration. Statistically significant differences were found only for cost (favoring clinically indicated replacement) and infiltration (occurring less with routine replacement). 

The largest and most robust RCT in the meta-analysis¹² was conducted by Rickard et al.¹³ (2012). Their nonblinded, intention-to-treat study of 3283 patients used concealed allocation to randomly assign patients to either clinically indicated or routine PIVC replacement in order to evaluate a primary endpoint, phlebitis. Secondary endpoints were CRBSI, venous port infection, IVC tip colonization, infusion failure, number of IVCs needed per patient, IV therapy duration, cost, and mortality. Need for PIVC replacement was methodically monitored (Table) with extensive nursing education and interrater validation. The study found no difference in the groups’ phlebitis rates; the rate was 7% for both routine and clinically indicated replacement (13.08% and 13.11%, respectively, adjusted for phlebitis per 1000 IVC days). In addition, there was no difference in the secondary outcome measures, except cost and number of catheters used, both of which favored clinically indicated replacement. The most serious complication, CRBSI, occurred at essentially the same rate in the 2 replacement arms: 0.11% (routine) and 0% (clinically indicated). Per-patient cost for the entire course of treatment was A$69.24 in the routine group and A$61.66 in the clinically indicated group; the difference was A$7.58 (P < 0.0001). Mean number of catheters used was 1.9 in the routine group and 1.7 in the clinically indicated group; the difference was 0.21 catheter per patient for the treatment course (P < 0.0001). Overall, the study found no important difference in significant outcomes between the 2 study arms.

The other 4 studies in the meta-analysis¹² duplicated these results, with none finding a higher rate of major adverse events.^14-17 All 4 showed virtually equivalent rates of phlebitis, the primary outcome; 3 also examined the secondary outcome measure of blood stream infection, and results were similar, with identical rates of complications. Only 1 trial identified any bloodstream infections (1 per group).¹⁵ The meta-analysis did find that routine catheter replacement resulted in less catheter infiltration. 

Most of the data on PIVC exchange involves phlebitis and other local complications. A prospective study by Stuart et al.¹⁸ and commentary by Collignon et al.¹⁹ underscore the need for further research targeting blood stream infections (sepsis and severe sepsis in particular) as a primary outcome. Blood stream infections, especially those related to PIVC use, are rare entities overall, with most recent data yielding an estimated rate of 0.5 per 1000 catheter-days.²⁰ Given this epidemiologic finding, researchers trying to acquire meaningful data on PIVC-related blood stream infections and subsequent complications would need to have tens of thousands of patients in routine and clinically indicated replacement arms to sufficiently power their studies.²⁰ As they are infeasible, such trials cannot be found in the scientific literature.

Stuart et al.¹⁸ tried addressing the question. Prospectively examining more than 5 million occupied-bed days and the incidence of bloodstream infections by type of intravascular device over a 5-year period, they found that 137 (23.5%) of 583 healthcare-associated Staphylococcus aureus bacteremia (SAB) cases were attributed to PIVC use. PIVC insertions were performed equally (39.6%) in emergency departments and medical wards. About 45% of PIVCs remained in place 4 days or longer. Stuart et al. noted the “significant issue of PIVC-associated SAB” and favored routine removal of PIVCs within 96 hours (4 days). However, 55% of patients in their PIVC-related SAB group had the device in place less than 4 days. In addition, overall incidence of SAB was low: 0.3 per 10,000 occupied-bed days. Further, their study did not adjust device-specific SAB incidence for frequency of device use. For example, the rate of healthcare-acquired SAB was 19.7% for central venous catheters and 23.5% for PIVCs, despite PIVCs being used significantly more often than central lines. Device-specific adjustments would show a vastly different absolute risk of SAB in relation to individual devices. Nevertheless, the overall benefit of and need for routine PIVC replacement must be questioned. The percentage of PIVC-associated SAB in their study and the need for more research in this area should be noted. Given current information, their study and others in the literature underscore the need for selective use, appropriate maintenance, and timely removal of PIVCs.

Pure clinical outcomes are important, but procedural costs are as well. Clinically indicated replacement helps patients avoid an unpleasant procedure and saves money.²¹ If one third of the 37 million annual inpatient admissions require a PIVC for more than 3 days, then a strategy of “replacement when clinically indicated” could prevent almost 2.5 million unnecessary PIVC insertions each year. Equipment cost savings combined with savings of nearly 1 million staff hours could yield an estimated $400 million in savings over a 5-year period.²² Given current data suggesting no harm from clinically indicated PIVC replacement and clear evidence that routine replacement increases needle sticks and costs, it seems time to end the practice of routine PIVC replacement.

Compared with clinically indicated catheter replacement, routine replacement in the absence of a clinical indication (eg, infiltration, phlebitis, infection) provides no added benefit. Studies have consistently found that rates of phlebitis and SAB are not affected by scheduled replacement, though the largest RCT may not have been powered to show a difference in SAB. The present authors’ recommendations for PIVC care are:

• Scrutinize each patient’s need for PIVCs and remove each PIVC as soon as possible.
• Do not make routine replacement of otherwise well-functioning, well-appearing clinically necessary PIVCs the standard of care.
• Regularly examine PIVC sites for signs and symptoms of infection.
• Remove a PIVC immediately on recognition of any clinical sign of a complication (eg, infiltration, phlebitis, localized infection, blood stream infection) and replace the PIVC only if there is a clinical need.
• If replacing PIVCs on a clinical basis, establish protocols for frequency of evaluation for complications; these protocols might mirror those from prior studies (Table).^10,22
• Replace as soon as possible any PIVC inserted during an urgent or emergent situation in which proper insertion technique could not be guaranteed.
• Conduct real-world observational studies to ensure that the switch to clinically driven replacement is safe and develop standardized definitions of complications.

Given the literature findings and the preceding recommendations, the authors conclude that the patient in the case example does not need routine PIVC replacement. His PIVC may remain in place as long as evaluation for local complications is routinely and methodically performed and the device is removed as soon as it is deemed unnecessary (transition to oral opioid therapy).

The long-standing practice of routinely replacing PIVCs every 72 to 96 hours during a hospital stay does not affect any meaningful clinical outcome. Specifically, data do not show that routine replacement prevents phlebitis or blood stream infections. Furthermore, routine PIVC replacement increases patient discomfort, uses resources unnecessarily, and raises hospital costs. Most of the PIVC research has involved phlebitis and other local complications; more research on PIVC use and bloodstream infections is needed. Given the findings in the current literature, routine PIVC replacement should be considered a Thing We Do For No Reason.

Disclosure

Nothing to report. 

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason”? Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason” topics by emailing TWDFNR@hospitalmedicine.org.

Soon, the checklist for internists seeing patients about to undergo surgery may include prescribing one of the lipid-lowering hydroxymethylglutaryl-CoA reductase inhibitors, also called statins.

Statins? Not long ago, we were debating whether patients who take statins should stop taking them before surgery, based on the manufacturers’ recommendations.¹ The discussion, however, has changed to whether patients who have never received a statin should be started on one before surgery to provide immediate prophylaxis against cardiac morbidity, and how much harm long-term statin users face if these drugs are withheld perioperatively.

The evidence is still very preliminary and based mostly on studies in animals and retrospective studies in people. However, an expanding body of indirect evidence suggests that these drugs are beneficial in this situation.

In this review, we discuss the mechanisms by which statins may protect the heart in the short term, drawing on data from animal and human studies of acute myocardial infarction, and we review the current (albeit limited) data from the perioperative setting.

FEW INTERVENTIONS DECREASE RISK

Each year, approximately 50,000 patients suffer a perioperative cardiovascular event; the incidence of myocardial infarction during or after noncardiac surgery is 2% to 3%.² The primary goal of preoperative cardiovascular risk assessment is to predict and avert these events.

But short of canceling surgery, few interventions have been found to reduce a patient’s risk. For example, a landmark study in 2004 cast doubt on the efficacy of preoperative coronary revascularization.³ Similarly, although early studies of beta-blockers were promising^4,5 and although most internists prescribe these drugs before surgery, more recent studies have cast doubt on their efficacy, particularly in patients at low risk undergoing intermediate-risk (rather than vascular) surgery.^6–8

This changing clinical landscape has prompted a search for new strategies for perioperative risk-reduction. Several recent studies have placed statins in the spotlight.

POTENTIAL MECHANISMS OF SHORT-TERM BENEFIT

Statins have been proven to save lives when used long-term, but how could this class of drugs, designed to prevent the accumulation of arterial plaques by lowering low-density lipoprotein cholesterol (LDL-C) levels, have any short-term impact on operative outcomes? Although LDL-C reduction is the principal mechanism of action of statins, not all of the benefit can be ascribed to this mechanism.⁹ The answer may lie in their “pleiotropic” effects—ie, actions other than LDL-C reduction.

The more immediate pleiotropic effects of statins in the proinflammatory and prothrombotic environment of the perioperative period are thought to include improved endothelial function (both antithrombotic function and vasomotor function in response to ischemic stress), enhanced stability of atherosclerotic plaques, decreased oxidative stress, and decreased vascular inflammation.^10–12

EVIDENCE FROM ANIMAL STUDIES

Experiments in animals suggest that statins, given shortly before or after a cardiovascular event, confer benefit before any changes in LDL-C are measurable.

Lefer et al¹³ found that simvastatin (Zocor), given 18 hours before an ischemic episode in rats, blunted the inflammatory response in cardiac reperfusion injury. Not only was reperfusion injury significantly less in the hearts of the rats that received simvastatin than in the saline control group, but the simvastatin-treated hearts also expressed fewer neutrophil adhesion molecules such as P-selectin, and they had more basal release of nitric oxide, the potent endothelial-derived vasodilator with antithrombotic, anti-inflammatory, and antiproliferative effects.¹⁴ These results suggest that statins may improve endothelial function acutely, particularly during ischemic stress.

Osborne et al¹⁵ fed rabbits a cholesterol-rich diet plus either lovastatin (Mevacor) or placebo. After 2 weeks, the rabbits underwent either surgery to induce a myocardial infarction or a sham procedure. Regardless of the pretreatment, biopsies of the aorta did not reveal any atherosclerosis; yet the lovastatin-treated rabbits sustained less myocardial ischemic damage and they had more endothelium-mediated vasodilatation.

Statin therapy also may improve cerebral ischemia outcomes in animal models.^14,16

Sironi et al¹⁶ induced strokes in rats by occluding the middle cerebral artery. The rats received either simvastatin or vehicle for 3 days before the stroke or immediately afterwards. Even though simvastatin did not have enough time to affect the total cholesterol level, rats treated with simvastatin had smaller infarcts (as measured by magnetic resonance imaging) and produced more nitric oxide.

Comment. Taken together, these studies offer tantalizing evidence that statins have short-term, beneficial nonlipid effects and may reduce not only the likelihood of an ischemic event, but—should one occur—the degree of tissue damage that ensues.

EFFECTS OF STATINS IN ACUTE CORONARY SYNDROME

The National Registry of Myocardial Infarction¹⁷ is a prospective, observational database of all patients with acute myocardial infarction admitted to 1,230 participating hospitals throughout the United States. In an analysis from this cohort, patients were divided into four groups: those receiving statins before and after admission, those receiving statins only before admission, those receiving statins only after admission, and those who never received statins.

Compared with those who never received statins, fewer patients who received them both before and after admission died while in the hospital (unadjusted odds ratio 0.23, 95% confidence interval [CI] 0.22–0.25), and the odds ratio for those who received statins for the first time was 0.31 (95% CI 0.29–0.33). Patients who stopped receiving a statin on admission were more likely to die than were patients who never received statins (odds ratio 1.09, 95% CI 1.03–1.15). These trends held true even when adjustments were made for potential confounding factors.

Comment. Unmeasured confounding factors (such as the inability to take pills due to altered mental status or the different practice styles of the providers who chose to discontinue statins) might have affected the results. Nevertheless, these results suggest that the protective effects of statins stop almost immediately when these drugs are discontinued, and that there may even be an adverse “rebound” effect when patients who have been taking these drugs for a long time stop taking them temporarily.

The Platelet Receptor Inhibition in Ischemic Syndrome Management trial,¹⁸ in a subgroup analysis, had nearly identical findings. In the main part of this trial, patients with coronary artery disease and chest pain at rest or accelerating pain in the last 24 hours were randomized to receive tirofiban (Aggrastat) or heparin. Complete data on statin use were available for 1,616 (50%) of the 3,232 patients in this trial, and the rate of the primary end point (death, myocardial infarction, or recurrent ischemia) was analyzed on the basis of statin therapy in this subgroup.

Comment. Together, these data lead to the conclusion that, when admitted for either acute myocardial infarction or acute coronary syndrome, patients already receiving statins should not have them stopped, and those who had not been receiving statins should receive them immediately. The safety of these medications in the acute setting appears excellent: in the Myocardial Ischemia Reduction With Acute Cholesterol Lowering (MIRACL)¹² and the Pravastatin or Atorvastatin Evaluation and Infection Therapy (PROVE-IT)¹¹ trials, fewer than 5% of statin-treated patients had transient elevations in transaminase levels, and no cases of rhabdomyolysis were reported.

PERIOPERATIVE STATIN STUDIES

The data on perioperative statin use are mostly observational and retrospective and fall into essentially four surgical categories: coronary artery bypass grafting (CABG), carotid endarterectomy,^19,20 noncardiac vascular surgery, and major noncardiac surgery. Two meta-analyses have also evaluated the data.^21,22 The only randomized controlled trial (performed by Durazzo et al²³) was small and was carried out at a single center in vascular surgery patients, and the event rate was low.

Current recommendations from the National Cholesterol Education Program (NCEP)²⁴ say that patients who need CABG, have peripheral arterial disease, have an abdominal aortic aneurysm, or have cerebrovascular disease should already be on a statin to achieve an LDL-C goal level of less than 100 mg/dL, with an optional goal of less than 70 mg/dL, independent of surgery.

Since not all patients who should be on statins are actually on them, questions arise:

• Is it important (and safe) to start statin treatment preoperatively?
• Will patients with cardiovascular risk factors but without known cardiovascular disease benefit from statins perioperatively?

Noncardiac vascular surgery

Multiple retrospective studies have evaluated the effect of statins in patients undergoing major noncardiac vascular surgery.^25–32

Kertai et al²⁵ evaluated 570 patients in Holland who underwent elective open surgery for infrarenal abdominal aortic aneurysms between 1991 and 2001, looking for an association between statin use and the incidence of perioperative death from myocardial infarction. Only 162 of the 570 patients had been on long-term statin therapy before the surgery. The use of statins was only one of many known baseline characteristics that were significantly different between the two groups, including age, body mass index, known coronary artery disease, and use of angiotensin-converting enzyme inhibitors and beta-blockers. In univariate analysis, statins appeared to be protective: 6 (3.7%) of the patients in the statin group died of a myocardial infarction, compared with 45 (11%) of those in the nostatin group. A multivariate analysis yielded similar findings, with an odds ratio of 0.24 (95% CI 0.11–0.54).

Ward et al²⁷ performed a very similar retrospective study, with similar findings. In 446 patients who underwent surgery for infrarenal abdominal aortic aneurysm, statin therapy was associated with a significantly lower incidence of the combined end point of death, myocardial infarction, stroke, and major peripheral vascular complications, with an adjusted odds ratio of 0.36 (95% CI 0.14–0.93).

Poldermans et al²⁶ noted similar findings in a case-control study of noncardiac vascular surgery patients. Statin users had a much lower perioperative risk of death than did nonusers, with an adjusted odds ratio of 0.22 (95% CI 0.10–0.47).

O’Neil-Callahan et al,²⁸ in a cohort study, found that statin users had fewer perioperative cardiac complications, with an adjusted odds ratio of 0.49 (95% CI 0.28–0.84, P = .009).

Le Manach et al³³ reviewed the outcomes for all patients of a single hospital in Paris who underwent nonemergency infrarenal aortic procedures between January 2001 and December 2004. In January 2004, the hospital instituted guidelines to ensure that patients on statins continue taking them up to the evening before surgery and that statins be restarted on the first postoperative day (via nasogastric tube if necessary). Before 2004, there had been no specific guidelines, and patients on statins did not receive them for a median of 4 days postoperatively. Types of procedures were similar during the two time periods, as were the rates of beta-blocker use, preoperative revascularization, venous thromboembolism prophylaxis, and perioperative blood pressure control. After surgery, topononin I levels were measured in all patients as surveillance for cardiac events, and were defined as elevated when greater than 0.2 ng/mL.

Compared with patients not on statins at all, those treated with statins continuously throughout the perioperative period (after January 2004) had a lower rate of elevated troponin (relative risk 0.38). In contrast, those who had their statins transiently discontinued perioperatively (prior to 2004) had troponin elevations more often than those who had never been treated (relative risk 2.1). This suggested an over fivefold risk reduction (P < .001) conferred by not discontinuing statins in the immediate postoperative period. This finding was maintained after multivariate adjustment: statin withdrawal was associated with a 2.9-fold (95% CI 1.6–5.5) increase in the risk of cardiac enzyme elevations postoperatively. No fewer deaths were noted, but the study was not powered to detect a mortality difference.

Comment. Although secular trends cannot be entirely discounted as contributing to these findings, the prompt increase in cardiac events after just 4 days of statin withdrawal adds to the growing body of evidence suggesting that statin discontinuation can have harmful acute effects. It also brings up the question: Can starting statins benefit patients in the same time period?

Should statins be started before vascular surgery?

Schouten et al³² evaluated the effects of newly started or continued statin treatment in patients undergoing major elective vascular surgery. Patients were screened before surgery and started on statins if they were not already receiving them and their total cholesterol levels were elevated; new users received the medication for about 40 days before surgery. Of the 981 screened patients, 44 (5%) were newly started on statins and 182 (19%) were continued on their therapy. Perioperative death or myocardial infarction occurred in 22 (8.8%) of the statin users and 111 (14.7%) of the nonusers, a statistically significant difference. Temporary discontinuation (median 1 day) of statins in this study due to the inability to take an oral medication did not appear to affect the likelihood of a myocardial infarction.

Durazzo et al²³ performed a single-center, randomized, prospective, placebo-controlled, double-blind clinical trial of atorvastatin (Lipitor) 20 mg daily vs placebo in 100 patients undergoing noncardiac arterial vascular surgery. Patients were excluded if they had previously used medications to treat dyslipidemia, recently had a cardiovascular event, or had contraindications to statin treatment such as a baseline creatinine level greater than 2.0 mg/dL or severe hepatic disease. The intervention group received atorvastatin starting at least 2 weeks before surgery for a total of 45 days. Patients were then continued or started on a statin after surgery if their LDL-C level was greater than 100 mg/dL. Beta-blocker use was recommended “on the basis of current guidelines.”

One month after surgery, the LDL-C level was statistically significantly lower in the atorvastatin group. Since most patients did not continue or start statin therapy after the 45-day treatment period, the LDL-C levels were not statistically different at 3 and 6 months after surgery.

At 6 months, the rate of the primary end point (death from cardiovascular causes, nonfatal acute myocardial infarction, ischemic stroke, or unstable angina) was 26.0% in the placebo group and 8.0% in the atorvastatin group, a statistically significant difference. Three patients in the atorvastatin group had cardiac events in the first 10 days after surgery, compared with 11 patients in the placebo group. Thirteen of the 17 total cardiac events took place within 10 days after surgery.

One of the atorvastatin patients developed rhabdomyolysis and elevated aminotransferase levels.

Major noncardiac surgery

Lindenauer et al² performed a retrospective cohort study of surgical patients who were at least 18 years old and survived beyond the second hospital day. Patients were divided into a group receiving any form of lipid-lowering treatment (of whom more than 90% were taking statins) and a group that had never never received a lipid-lowering drug or only started one on the third day of the hospitalization or later. The period of study was from January 1, 2000, to December 31, 2001.

In all, 780,591 patients from 329 hospitals throughout the United States were included, of whom only 77,082 (9.9%) received lipid-lowering therapy. Eight percent of the patients underwent vascular surgery. Not surprisingly, the treated patients were more likely to have a history of hypertension, diabetes, ischemic heart disease, or hyperlipidemia. They also were more likely to have a vascular procedure performed, to have two or more cardiac risk factors (high-risk surgery, ischemic heart disease, congestive heart failure, cerebrovascular disease, renal insufficiency, or diabetes mellitus), and to be treated with beta-blockers and angiotensin-converting enzyme inhibitors, but they were less likely to have high-risk and emergency surgery performed.

The primary end point, perioperative death, occurred in 2.13% of the treated patients and 3.05% of the nontreated group. Compared with the rate in a propensity-matched cohort, the odds ratio adjusted for unbalanced covariates was 0.62 (95% CI 0.58–0.67) in favor of lipid treatment. Stratification by cardiac risk index revealed a number needed to treat of 186 for those with no risk factors, 60 for those with two risk factors, and 30 for those with four or more risk factors.

Unfortunately, this analysis was not able to take into account whether and for how long patients were receiving lipid-lowering therapy before hospitalization. It therefore does not answer the questions of whether starting lipid-lowering therapy before surgery is beneficial or whether stopping it is harmful. It also does not shed light on whether perioperative lipid-lowering increases the risk of rhabdomyolysis or liver disease.

Two recent retrospective cohort studies evaluated the outcomes in patients undergoing carotid endarterectomy.^19,20

Kennedy et al¹⁹ found that patients on a statin at the time of admission who had symptomatic carotid disease had lower rates of inhospital death (adjusted odds ratio 0.24, 95% CI 0.06–0.91) and ischemic stroke or death (adjusted odds ratio 0.55, 95% CI 0.31–0.97). However, cardiac outcomes among these symptomatic patients were not significantly improved (odds ratio 0.82, 95% CI 0.45–1.50), nor was there benefit for asymptomatic patients, raising the possibility that the positive findings were due to chance or that patients at lower baseline risk for vascular events may have less benefit.

McGirt et al²⁰ performed a similar study; they did not, however, distinguish whether patients had symptomatic vs asymptomatic carotid disease. The 30-day risk of perioperative stroke was lower in patients treated with a statin, with an odds ratio of 0.41 (95% CI 0.18–0.93); the odds ratio for death was 0.21 (95% CI 0.05–0.96). Cardiac outcomes were not significantly affected.

Coronary artery bypass graft surgery

According to the NCEP recommendations, nearly all patients undergoing CABG should already be on a statin before surgery since they all have known coronary artery disease. Multiple observational studies have offered confirmatory evidence that statins are beneficial in this setting.^34–38

Liakopoulos et al³⁹ evaluated whether the anti-inflammatory effects of statins may, in part, account for their beneficial effect in the perioperative period. The authors prospectively matched 18 patients who were taking statins and were referred for elective CABG with 18 patients who were not prescribed statins previously. The only major measured baseline characteristic that differed between the two groups was a statistically significantly lower LDL-C level in the statin group. The operative characteristics did not differ, and cytokine levels at baseline were similar.

Tumor necrosis factor alpha levels increased significantly in the control group but did not change significantly in the statin group. Interleukin 8 increased in both groups by a similar amount. Interleukin 6 (the major inducer of C-reactive protein) increased from baseline in both groups but did not increase nearly as much in the statin group as in the control group; the intergroup difference was statistically significant. The anti-inflammatory cytokine interleukin 10 increased minimally from baseline in the control group, while the statin group’s levels increased significantly above baseline and those of the control group.

Christenson⁴⁰ also found that inflammatory markers were improved with pre-CABG statin treatment in a small randomized trial in which patients received simvastatin 20 mg 4 weeks prior to CABG surgery vs no statin. Interestingly, far fewer statin-treated patients developed thrombocytosis (platelet count > 400 × 10⁹/L) than did control patients (3% vs 81%, P < .0001).

RISKS OF PERIOPERATIVE STATINS

The risks associated with statin therapy in general appear low, but specific perioperative risks have not been well studied.

Baigent et al,⁴¹ in a meta-analysis of randomized trials of nonperioperative statin therapy, found that rhabdomyolysis occurred in 9 (0.023%) of 39,884 patients receiving statins vs 6 (0.015%) of the 39,817 controls, with a number needed to harm of 12,500. Moreover, the rates of nonvascular death and cancer did not increase. It is plausible that the risk is somewhat greater in the perioperative setting but is likely not enough to outweigh the potential benefits, especially since the risk of ischemic vascular events is particularly high then.

Some of the perioperative studies cited above specifically addressed potential risks. For example, in the study by Schouten et al,³² mild creatine kinase elevations were more common in the statin-treated group, but the incidence of moderate and severe creatine kinase elevations did not differ significantly. No case of rhabdomyolysis occurred, and length of surgery was the only predictor of myopathy. MIRACL and PROVE-IT revealed similar safety profiles; aminotransferase levels normalized when statins were stopped, and no cases of rhabdomyolysis occurred.^11,12 In the vascular surgery study by Durazzo et al,²³ 1 (2%) of the 50 atorvastatin-treated patients developed both rhabdomyolysis and elevated aminotransferase levels that prompted discontinuation of the statin.

Overall, the observational studies do not indicate that statin continuation or treatment is harmful in perioperative patients. However, these studies did not specifically evaluate patients with acute insults from surgery such as sepsis, renal failure, or hepatitis. It is unknown what effect statin therapy would have in those patients and whether statins should be selectively discontinued in patients who develop major hepatic, musculoskeletal, or renal complications after surgery.

OUR RECOMMENDATIONS

Before CABG or vascular surgery

Given the NCEP recommendations, existing primary and secondary prevention studies, observational studies of CABG and noncardiac vascular surgery patients, and the one randomized trial of vascular surgery patients, data support the use of statins in nearly all patients undergoing cardiac or vascular surgery. We advocate starting statins in the perioperative period to take advantage of their rapid-acting pleiotropic effects, and continuing them long-term to take advantage of their lipid-lowering effects. This recommendation is in line with the recently released American College of Cardiology/American Heart Association (ACC/AHA) 2007 perioperative guidelines that state “for patients undergoing vascular surgery with or without clinical risk factors, statin use is reasonable.”⁴²

Although the ideal time to start statins is not certain, the study by Durazzo et al²³ suggests that they should be started at least 2 weeks before surgery if possible. Moreover, patients already taking statins should definitely not have their statins discontinued if at all possible.

Before major nonvascular surgery

For patients undergoing major nonvascular (intermediate-risk) surgery, physicians should first ascertain if the patient has an indication for statin therapy based on current nonsurgical lipid level recommendations. However, even if there is no clear indication for statin therapy based on NCEP guidelines, we endorse the recently released ACC/AHA perioperative guidelines that state that statin therapy can be considered in patients with a risk factor who are undergoing intermediate-risk procedures. Moreover, we wholeheartedly support the ACC/AHA’s strongest recommendation that patients who are already receiving statins and are undergoing noncardiac surgery should not have their statins discontinued.

When to discontinue statins?

The risk of harm overall appears to be minimal and certainly less than the likelihood of benefit. It is reasonable to observe patients postoperatively for adverse clinical events that may increase the risk of perioperative statin treatment, such as acute renal failure, hepatic failure, or sepsis, but whether statins should be stopped in patients with these complications remains unknown; we advocate individualizing the decision.

More studies needed

We need more data on whether moderate-risk patients undergoing moderate-risk surgery benefit from perioperative statin therapy, when therapy should be started, whether therapy should be started on the day of surgery if it was not started earlier, which statin and what doses are optimal, how long therapy should be continued, and what degree of risk is associated with perioperative statin therapy.

Fortunately, important data should be forthcoming in the next few years: the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE-IV) study⁴³ is a 4-year two-by-two factorial placebo-controlled study evaluating the use of fluvastatin (Lescol) and bisoprolol (Zebeta, a beta-blocker) separately and together in patients who are older than 40 years, are undergoing elective noncardiac surgery, have an estimated risk of cardiovascular death of more than 1%, have not used statins previously, and do not have elevated cholesterol.

Soon, the checklist for internists seeing patients about to undergo surgery may include prescribing one of the lipid-lowering hydroxymethylglutaryl-CoA reductase inhibitors, also called statins.

Statins? Not long ago, we were debating whether patients who take statins should stop taking them before surgery, based on the manufacturers’ recommendations.¹ The discussion, however, has changed to whether patients who have never received a statin should be started on one before surgery to provide immediate prophylaxis against cardiac morbidity, and how much harm long-term statin users face if these drugs are withheld perioperatively.

The evidence is still very preliminary and based mostly on studies in animals and retrospective studies in people. However, an expanding body of indirect evidence suggests that these drugs are beneficial in this situation.

In this review, we discuss the mechanisms by which statins may protect the heart in the short term, drawing on data from animal and human studies of acute myocardial infarction, and we review the current (albeit limited) data from the perioperative setting.

FEW INTERVENTIONS DECREASE RISK

Each year, approximately 50,000 patients suffer a perioperative cardiovascular event; the incidence of myocardial infarction during or after noncardiac surgery is 2% to 3%.² The primary goal of preoperative cardiovascular risk assessment is to predict and avert these events.

But short of canceling surgery, few interventions have been found to reduce a patient’s risk. For example, a landmark study in 2004 cast doubt on the efficacy of preoperative coronary revascularization.³ Similarly, although early studies of beta-blockers were promising^4,5 and although most internists prescribe these drugs before surgery, more recent studies have cast doubt on their efficacy, particularly in patients at low risk undergoing intermediate-risk (rather than vascular) surgery.^6–8

This changing clinical landscape has prompted a search for new strategies for perioperative risk-reduction. Several recent studies have placed statins in the spotlight.

POTENTIAL MECHANISMS OF SHORT-TERM BENEFIT

Statins have been proven to save lives when used long-term, but how could this class of drugs, designed to prevent the accumulation of arterial plaques by lowering low-density lipoprotein cholesterol (LDL-C) levels, have any short-term impact on operative outcomes? Although LDL-C reduction is the principal mechanism of action of statins, not all of the benefit can be ascribed to this mechanism.⁹ The answer may lie in their “pleiotropic” effects—ie, actions other than LDL-C reduction.

The more immediate pleiotropic effects of statins in the proinflammatory and prothrombotic environment of the perioperative period are thought to include improved endothelial function (both antithrombotic function and vasomotor function in response to ischemic stress), enhanced stability of atherosclerotic plaques, decreased oxidative stress, and decreased vascular inflammation.^10–12

EVIDENCE FROM ANIMAL STUDIES

Experiments in animals suggest that statins, given shortly before or after a cardiovascular event, confer benefit before any changes in LDL-C are measurable.

Lefer et al¹³ found that simvastatin (Zocor), given 18 hours before an ischemic episode in rats, blunted the inflammatory response in cardiac reperfusion injury. Not only was reperfusion injury significantly less in the hearts of the rats that received simvastatin than in the saline control group, but the simvastatin-treated hearts also expressed fewer neutrophil adhesion molecules such as P-selectin, and they had more basal release of nitric oxide, the potent endothelial-derived vasodilator with antithrombotic, anti-inflammatory, and antiproliferative effects.¹⁴ These results suggest that statins may improve endothelial function acutely, particularly during ischemic stress.

Osborne et al¹⁵ fed rabbits a cholesterol-rich diet plus either lovastatin (Mevacor) or placebo. After 2 weeks, the rabbits underwent either surgery to induce a myocardial infarction or a sham procedure. Regardless of the pretreatment, biopsies of the aorta did not reveal any atherosclerosis; yet the lovastatin-treated rabbits sustained less myocardial ischemic damage and they had more endothelium-mediated vasodilatation.

Statin therapy also may improve cerebral ischemia outcomes in animal models.^14,16

Sironi et al¹⁶ induced strokes in rats by occluding the middle cerebral artery. The rats received either simvastatin or vehicle for 3 days before the stroke or immediately afterwards. Even though simvastatin did not have enough time to affect the total cholesterol level, rats treated with simvastatin had smaller infarcts (as measured by magnetic resonance imaging) and produced more nitric oxide.

Comment. Taken together, these studies offer tantalizing evidence that statins have short-term, beneficial nonlipid effects and may reduce not only the likelihood of an ischemic event, but—should one occur—the degree of tissue damage that ensues.

EFFECTS OF STATINS IN ACUTE CORONARY SYNDROME

The National Registry of Myocardial Infarction¹⁷ is a prospective, observational database of all patients with acute myocardial infarction admitted to 1,230 participating hospitals throughout the United States. In an analysis from this cohort, patients were divided into four groups: those receiving statins before and after admission, those receiving statins only before admission, those receiving statins only after admission, and those who never received statins.

Compared with those who never received statins, fewer patients who received them both before and after admission died while in the hospital (unadjusted odds ratio 0.23, 95% confidence interval [CI] 0.22–0.25), and the odds ratio for those who received statins for the first time was 0.31 (95% CI 0.29–0.33). Patients who stopped receiving a statin on admission were more likely to die than were patients who never received statins (odds ratio 1.09, 95% CI 1.03–1.15). These trends held true even when adjustments were made for potential confounding factors.

Comment. Unmeasured confounding factors (such as the inability to take pills due to altered mental status or the different practice styles of the providers who chose to discontinue statins) might have affected the results. Nevertheless, these results suggest that the protective effects of statins stop almost immediately when these drugs are discontinued, and that there may even be an adverse “rebound” effect when patients who have been taking these drugs for a long time stop taking them temporarily.

The Platelet Receptor Inhibition in Ischemic Syndrome Management trial,¹⁸ in a subgroup analysis, had nearly identical findings. In the main part of this trial, patients with coronary artery disease and chest pain at rest or accelerating pain in the last 24 hours were randomized to receive tirofiban (Aggrastat) or heparin. Complete data on statin use were available for 1,616 (50%) of the 3,232 patients in this trial, and the rate of the primary end point (death, myocardial infarction, or recurrent ischemia) was analyzed on the basis of statin therapy in this subgroup.

Comment. Together, these data lead to the conclusion that, when admitted for either acute myocardial infarction or acute coronary syndrome, patients already receiving statins should not have them stopped, and those who had not been receiving statins should receive them immediately. The safety of these medications in the acute setting appears excellent: in the Myocardial Ischemia Reduction With Acute Cholesterol Lowering (MIRACL)¹² and the Pravastatin or Atorvastatin Evaluation and Infection Therapy (PROVE-IT)¹¹ trials, fewer than 5% of statin-treated patients had transient elevations in transaminase levels, and no cases of rhabdomyolysis were reported.

PERIOPERATIVE STATIN STUDIES

The data on perioperative statin use are mostly observational and retrospective and fall into essentially four surgical categories: coronary artery bypass grafting (CABG), carotid endarterectomy,^19,20 noncardiac vascular surgery, and major noncardiac surgery. Two meta-analyses have also evaluated the data.^21,22 The only randomized controlled trial (performed by Durazzo et al²³) was small and was carried out at a single center in vascular surgery patients, and the event rate was low.

Current recommendations from the National Cholesterol Education Program (NCEP)²⁴ say that patients who need CABG, have peripheral arterial disease, have an abdominal aortic aneurysm, or have cerebrovascular disease should already be on a statin to achieve an LDL-C goal level of less than 100 mg/dL, with an optional goal of less than 70 mg/dL, independent of surgery.

Since not all patients who should be on statins are actually on them, questions arise:

• Is it important (and safe) to start statin treatment preoperatively?
• Will patients with cardiovascular risk factors but without known cardiovascular disease benefit from statins perioperatively?

Noncardiac vascular surgery

Multiple retrospective studies have evaluated the effect of statins in patients undergoing major noncardiac vascular surgery.^25–32

Kertai et al²⁵ evaluated 570 patients in Holland who underwent elective open surgery for infrarenal abdominal aortic aneurysms between 1991 and 2001, looking for an association between statin use and the incidence of perioperative death from myocardial infarction. Only 162 of the 570 patients had been on long-term statin therapy before the surgery. The use of statins was only one of many known baseline characteristics that were significantly different between the two groups, including age, body mass index, known coronary artery disease, and use of angiotensin-converting enzyme inhibitors and beta-blockers. In univariate analysis, statins appeared to be protective: 6 (3.7%) of the patients in the statin group died of a myocardial infarction, compared with 45 (11%) of those in the nostatin group. A multivariate analysis yielded similar findings, with an odds ratio of 0.24 (95% CI 0.11–0.54).

Ward et al²⁷ performed a very similar retrospective study, with similar findings. In 446 patients who underwent surgery for infrarenal abdominal aortic aneurysm, statin therapy was associated with a significantly lower incidence of the combined end point of death, myocardial infarction, stroke, and major peripheral vascular complications, with an adjusted odds ratio of 0.36 (95% CI 0.14–0.93).

Poldermans et al²⁶ noted similar findings in a case-control study of noncardiac vascular surgery patients. Statin users had a much lower perioperative risk of death than did nonusers, with an adjusted odds ratio of 0.22 (95% CI 0.10–0.47).

O’Neil-Callahan et al,²⁸ in a cohort study, found that statin users had fewer perioperative cardiac complications, with an adjusted odds ratio of 0.49 (95% CI 0.28–0.84, P = .009).

Le Manach et al³³ reviewed the outcomes for all patients of a single hospital in Paris who underwent nonemergency infrarenal aortic procedures between January 2001 and December 2004. In January 2004, the hospital instituted guidelines to ensure that patients on statins continue taking them up to the evening before surgery and that statins be restarted on the first postoperative day (via nasogastric tube if necessary). Before 2004, there had been no specific guidelines, and patients on statins did not receive them for a median of 4 days postoperatively. Types of procedures were similar during the two time periods, as were the rates of beta-blocker use, preoperative revascularization, venous thromboembolism prophylaxis, and perioperative blood pressure control. After surgery, topononin I levels were measured in all patients as surveillance for cardiac events, and were defined as elevated when greater than 0.2 ng/mL.

Compared with patients not on statins at all, those treated with statins continuously throughout the perioperative period (after January 2004) had a lower rate of elevated troponin (relative risk 0.38). In contrast, those who had their statins transiently discontinued perioperatively (prior to 2004) had troponin elevations more often than those who had never been treated (relative risk 2.1). This suggested an over fivefold risk reduction (P < .001) conferred by not discontinuing statins in the immediate postoperative period. This finding was maintained after multivariate adjustment: statin withdrawal was associated with a 2.9-fold (95% CI 1.6–5.5) increase in the risk of cardiac enzyme elevations postoperatively. No fewer deaths were noted, but the study was not powered to detect a mortality difference.

Comment. Although secular trends cannot be entirely discounted as contributing to these findings, the prompt increase in cardiac events after just 4 days of statin withdrawal adds to the growing body of evidence suggesting that statin discontinuation can have harmful acute effects. It also brings up the question: Can starting statins benefit patients in the same time period?

Should statins be started before vascular surgery?

Schouten et al³² evaluated the effects of newly started or continued statin treatment in patients undergoing major elective vascular surgery. Patients were screened before surgery and started on statins if they were not already receiving them and their total cholesterol levels were elevated; new users received the medication for about 40 days before surgery. Of the 981 screened patients, 44 (5%) were newly started on statins and 182 (19%) were continued on their therapy. Perioperative death or myocardial infarction occurred in 22 (8.8%) of the statin users and 111 (14.7%) of the nonusers, a statistically significant difference. Temporary discontinuation (median 1 day) of statins in this study due to the inability to take an oral medication did not appear to affect the likelihood of a myocardial infarction.

Durazzo et al²³ performed a single-center, randomized, prospective, placebo-controlled, double-blind clinical trial of atorvastatin (Lipitor) 20 mg daily vs placebo in 100 patients undergoing noncardiac arterial vascular surgery. Patients were excluded if they had previously used medications to treat dyslipidemia, recently had a cardiovascular event, or had contraindications to statin treatment such as a baseline creatinine level greater than 2.0 mg/dL or severe hepatic disease. The intervention group received atorvastatin starting at least 2 weeks before surgery for a total of 45 days. Patients were then continued or started on a statin after surgery if their LDL-C level was greater than 100 mg/dL. Beta-blocker use was recommended “on the basis of current guidelines.”

One month after surgery, the LDL-C level was statistically significantly lower in the atorvastatin group. Since most patients did not continue or start statin therapy after the 45-day treatment period, the LDL-C levels were not statistically different at 3 and 6 months after surgery.

At 6 months, the rate of the primary end point (death from cardiovascular causes, nonfatal acute myocardial infarction, ischemic stroke, or unstable angina) was 26.0% in the placebo group and 8.0% in the atorvastatin group, a statistically significant difference. Three patients in the atorvastatin group had cardiac events in the first 10 days after surgery, compared with 11 patients in the placebo group. Thirteen of the 17 total cardiac events took place within 10 days after surgery.

One of the atorvastatin patients developed rhabdomyolysis and elevated aminotransferase levels.

Major noncardiac surgery

Lindenauer et al² performed a retrospective cohort study of surgical patients who were at least 18 years old and survived beyond the second hospital day. Patients were divided into a group receiving any form of lipid-lowering treatment (of whom more than 90% were taking statins) and a group that had never never received a lipid-lowering drug or only started one on the third day of the hospitalization or later. The period of study was from January 1, 2000, to December 31, 2001.

In all, 780,591 patients from 329 hospitals throughout the United States were included, of whom only 77,082 (9.9%) received lipid-lowering therapy. Eight percent of the patients underwent vascular surgery. Not surprisingly, the treated patients were more likely to have a history of hypertension, diabetes, ischemic heart disease, or hyperlipidemia. They also were more likely to have a vascular procedure performed, to have two or more cardiac risk factors (high-risk surgery, ischemic heart disease, congestive heart failure, cerebrovascular disease, renal insufficiency, or diabetes mellitus), and to be treated with beta-blockers and angiotensin-converting enzyme inhibitors, but they were less likely to have high-risk and emergency surgery performed.

The primary end point, perioperative death, occurred in 2.13% of the treated patients and 3.05% of the nontreated group. Compared with the rate in a propensity-matched cohort, the odds ratio adjusted for unbalanced covariates was 0.62 (95% CI 0.58–0.67) in favor of lipid treatment. Stratification by cardiac risk index revealed a number needed to treat of 186 for those with no risk factors, 60 for those with two risk factors, and 30 for those with four or more risk factors.

Unfortunately, this analysis was not able to take into account whether and for how long patients were receiving lipid-lowering therapy before hospitalization. It therefore does not answer the questions of whether starting lipid-lowering therapy before surgery is beneficial or whether stopping it is harmful. It also does not shed light on whether perioperative lipid-lowering increases the risk of rhabdomyolysis or liver disease.

Two recent retrospective cohort studies evaluated the outcomes in patients undergoing carotid endarterectomy.^19,20

Kennedy et al¹⁹ found that patients on a statin at the time of admission who had symptomatic carotid disease had lower rates of inhospital death (adjusted odds ratio 0.24, 95% CI 0.06–0.91) and ischemic stroke or death (adjusted odds ratio 0.55, 95% CI 0.31–0.97). However, cardiac outcomes among these symptomatic patients were not significantly improved (odds ratio 0.82, 95% CI 0.45–1.50), nor was there benefit for asymptomatic patients, raising the possibility that the positive findings were due to chance or that patients at lower baseline risk for vascular events may have less benefit.

McGirt et al²⁰ performed a similar study; they did not, however, distinguish whether patients had symptomatic vs asymptomatic carotid disease. The 30-day risk of perioperative stroke was lower in patients treated with a statin, with an odds ratio of 0.41 (95% CI 0.18–0.93); the odds ratio for death was 0.21 (95% CI 0.05–0.96). Cardiac outcomes were not significantly affected.

Coronary artery bypass graft surgery

According to the NCEP recommendations, nearly all patients undergoing CABG should already be on a statin before surgery since they all have known coronary artery disease. Multiple observational studies have offered confirmatory evidence that statins are beneficial in this setting.^34–38

Liakopoulos et al³⁹ evaluated whether the anti-inflammatory effects of statins may, in part, account for their beneficial effect in the perioperative period. The authors prospectively matched 18 patients who were taking statins and were referred for elective CABG with 18 patients who were not prescribed statins previously. The only major measured baseline characteristic that differed between the two groups was a statistically significantly lower LDL-C level in the statin group. The operative characteristics did not differ, and cytokine levels at baseline were similar.

Tumor necrosis factor alpha levels increased significantly in the control group but did not change significantly in the statin group. Interleukin 8 increased in both groups by a similar amount. Interleukin 6 (the major inducer of C-reactive protein) increased from baseline in both groups but did not increase nearly as much in the statin group as in the control group; the intergroup difference was statistically significant. The anti-inflammatory cytokine interleukin 10 increased minimally from baseline in the control group, while the statin group’s levels increased significantly above baseline and those of the control group.

Christenson⁴⁰ also found that inflammatory markers were improved with pre-CABG statin treatment in a small randomized trial in which patients received simvastatin 20 mg 4 weeks prior to CABG surgery vs no statin. Interestingly, far fewer statin-treated patients developed thrombocytosis (platelet count > 400 × 10⁹/L) than did control patients (3% vs 81%, P < .0001).

RISKS OF PERIOPERATIVE STATINS

The risks associated with statin therapy in general appear low, but specific perioperative risks have not been well studied.

Baigent et al,⁴¹ in a meta-analysis of randomized trials of nonperioperative statin therapy, found that rhabdomyolysis occurred in 9 (0.023%) of 39,884 patients receiving statins vs 6 (0.015%) of the 39,817 controls, with a number needed to harm of 12,500. Moreover, the rates of nonvascular death and cancer did not increase. It is plausible that the risk is somewhat greater in the perioperative setting but is likely not enough to outweigh the potential benefits, especially since the risk of ischemic vascular events is particularly high then.

Some of the perioperative studies cited above specifically addressed potential risks. For example, in the study by Schouten et al,³² mild creatine kinase elevations were more common in the statin-treated group, but the incidence of moderate and severe creatine kinase elevations did not differ significantly. No case of rhabdomyolysis occurred, and length of surgery was the only predictor of myopathy. MIRACL and PROVE-IT revealed similar safety profiles; aminotransferase levels normalized when statins were stopped, and no cases of rhabdomyolysis occurred.^11,12 In the vascular surgery study by Durazzo et al,²³ 1 (2%) of the 50 atorvastatin-treated patients developed both rhabdomyolysis and elevated aminotransferase levels that prompted discontinuation of the statin.

Overall, the observational studies do not indicate that statin continuation or treatment is harmful in perioperative patients. However, these studies did not specifically evaluate patients with acute insults from surgery such as sepsis, renal failure, or hepatitis. It is unknown what effect statin therapy would have in those patients and whether statins should be selectively discontinued in patients who develop major hepatic, musculoskeletal, or renal complications after surgery.

OUR RECOMMENDATIONS

Before CABG or vascular surgery

Given the NCEP recommendations, existing primary and secondary prevention studies, observational studies of CABG and noncardiac vascular surgery patients, and the one randomized trial of vascular surgery patients, data support the use of statins in nearly all patients undergoing cardiac or vascular surgery. We advocate starting statins in the perioperative period to take advantage of their rapid-acting pleiotropic effects, and continuing them long-term to take advantage of their lipid-lowering effects. This recommendation is in line with the recently released American College of Cardiology/American Heart Association (ACC/AHA) 2007 perioperative guidelines that state “for patients undergoing vascular surgery with or without clinical risk factors, statin use is reasonable.”⁴²

Although the ideal time to start statins is not certain, the study by Durazzo et al²³ suggests that they should be started at least 2 weeks before surgery if possible. Moreover, patients already taking statins should definitely not have their statins discontinued if at all possible.

Before major nonvascular surgery

For patients undergoing major nonvascular (intermediate-risk) surgery, physicians should first ascertain if the patient has an indication for statin therapy based on current nonsurgical lipid level recommendations. However, even if there is no clear indication for statin therapy based on NCEP guidelines, we endorse the recently released ACC/AHA perioperative guidelines that state that statin therapy can be considered in patients with a risk factor who are undergoing intermediate-risk procedures. Moreover, we wholeheartedly support the ACC/AHA’s strongest recommendation that patients who are already receiving statins and are undergoing noncardiac surgery should not have their statins discontinued.

When to discontinue statins?

The risk of harm overall appears to be minimal and certainly less than the likelihood of benefit. It is reasonable to observe patients postoperatively for adverse clinical events that may increase the risk of perioperative statin treatment, such as acute renal failure, hepatic failure, or sepsis, but whether statins should be stopped in patients with these complications remains unknown; we advocate individualizing the decision.

More studies needed

We need more data on whether moderate-risk patients undergoing moderate-risk surgery benefit from perioperative statin therapy, when therapy should be started, whether therapy should be started on the day of surgery if it was not started earlier, which statin and what doses are optimal, how long therapy should be continued, and what degree of risk is associated with perioperative statin therapy.

Fortunately, important data should be forthcoming in the next few years: the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE-IV) study⁴³ is a 4-year two-by-two factorial placebo-controlled study evaluating the use of fluvastatin (Lescol) and bisoprolol (Zebeta, a beta-blocker) separately and together in patients who are older than 40 years, are undergoing elective noncardiac surgery, have an estimated risk of cardiovascular death of more than 1%, have not used statins previously, and do not have elevated cholesterol.

Soon, the checklist for internists seeing patients about to undergo surgery may include prescribing one of the lipid-lowering hydroxymethylglutaryl-CoA reductase inhibitors, also called statins.

Statins? Not long ago, we were debating whether patients who take statins should stop taking them before surgery, based on the manufacturers’ recommendations.¹ The discussion, however, has changed to whether patients who have never received a statin should be started on one before surgery to provide immediate prophylaxis against cardiac morbidity, and how much harm long-term statin users face if these drugs are withheld perioperatively.

The evidence is still very preliminary and based mostly on studies in animals and retrospective studies in people. However, an expanding body of indirect evidence suggests that these drugs are beneficial in this situation.

In this review, we discuss the mechanisms by which statins may protect the heart in the short term, drawing on data from animal and human studies of acute myocardial infarction, and we review the current (albeit limited) data from the perioperative setting.

FEW INTERVENTIONS DECREASE RISK

Each year, approximately 50,000 patients suffer a perioperative cardiovascular event; the incidence of myocardial infarction during or after noncardiac surgery is 2% to 3%.² The primary goal of preoperative cardiovascular risk assessment is to predict and avert these events.

But short of canceling surgery, few interventions have been found to reduce a patient’s risk. For example, a landmark study in 2004 cast doubt on the efficacy of preoperative coronary revascularization.³ Similarly, although early studies of beta-blockers were promising^4,5 and although most internists prescribe these drugs before surgery, more recent studies have cast doubt on their efficacy, particularly in patients at low risk undergoing intermediate-risk (rather than vascular) surgery.^6–8

This changing clinical landscape has prompted a search for new strategies for perioperative risk-reduction. Several recent studies have placed statins in the spotlight.

POTENTIAL MECHANISMS OF SHORT-TERM BENEFIT

Statins have been proven to save lives when used long-term, but how could this class of drugs, designed to prevent the accumulation of arterial plaques by lowering low-density lipoprotein cholesterol (LDL-C) levels, have any short-term impact on operative outcomes? Although LDL-C reduction is the principal mechanism of action of statins, not all of the benefit can be ascribed to this mechanism.⁹ The answer may lie in their “pleiotropic” effects—ie, actions other than LDL-C reduction.

The more immediate pleiotropic effects of statins in the proinflammatory and prothrombotic environment of the perioperative period are thought to include improved endothelial function (both antithrombotic function and vasomotor function in response to ischemic stress), enhanced stability of atherosclerotic plaques, decreased oxidative stress, and decreased vascular inflammation.^10–12

EVIDENCE FROM ANIMAL STUDIES

Experiments in animals suggest that statins, given shortly before or after a cardiovascular event, confer benefit before any changes in LDL-C are measurable.

Lefer et al¹³ found that simvastatin (Zocor), given 18 hours before an ischemic episode in rats, blunted the inflammatory response in cardiac reperfusion injury. Not only was reperfusion injury significantly less in the hearts of the rats that received simvastatin than in the saline control group, but the simvastatin-treated hearts also expressed fewer neutrophil adhesion molecules such as P-selectin, and they had more basal release of nitric oxide, the potent endothelial-derived vasodilator with antithrombotic, anti-inflammatory, and antiproliferative effects.¹⁴ These results suggest that statins may improve endothelial function acutely, particularly during ischemic stress.

Osborne et al¹⁵ fed rabbits a cholesterol-rich diet plus either lovastatin (Mevacor) or placebo. After 2 weeks, the rabbits underwent either surgery to induce a myocardial infarction or a sham procedure. Regardless of the pretreatment, biopsies of the aorta did not reveal any atherosclerosis; yet the lovastatin-treated rabbits sustained less myocardial ischemic damage and they had more endothelium-mediated vasodilatation.

Statin therapy also may improve cerebral ischemia outcomes in animal models.^14,16

Sironi et al¹⁶ induced strokes in rats by occluding the middle cerebral artery. The rats received either simvastatin or vehicle for 3 days before the stroke or immediately afterwards. Even though simvastatin did not have enough time to affect the total cholesterol level, rats treated with simvastatin had smaller infarcts (as measured by magnetic resonance imaging) and produced more nitric oxide.

Comment. Taken together, these studies offer tantalizing evidence that statins have short-term, beneficial nonlipid effects and may reduce not only the likelihood of an ischemic event, but—should one occur—the degree of tissue damage that ensues.

EFFECTS OF STATINS IN ACUTE CORONARY SYNDROME

The National Registry of Myocardial Infarction¹⁷ is a prospective, observational database of all patients with acute myocardial infarction admitted to 1,230 participating hospitals throughout the United States. In an analysis from this cohort, patients were divided into four groups: those receiving statins before and after admission, those receiving statins only before admission, those receiving statins only after admission, and those who never received statins.

Compared with those who never received statins, fewer patients who received them both before and after admission died while in the hospital (unadjusted odds ratio 0.23, 95% confidence interval [CI] 0.22–0.25), and the odds ratio for those who received statins for the first time was 0.31 (95% CI 0.29–0.33). Patients who stopped receiving a statin on admission were more likely to die than were patients who never received statins (odds ratio 1.09, 95% CI 1.03–1.15). These trends held true even when adjustments were made for potential confounding factors.

Comment. Unmeasured confounding factors (such as the inability to take pills due to altered mental status or the different practice styles of the providers who chose to discontinue statins) might have affected the results. Nevertheless, these results suggest that the protective effects of statins stop almost immediately when these drugs are discontinued, and that there may even be an adverse “rebound” effect when patients who have been taking these drugs for a long time stop taking them temporarily.

The Platelet Receptor Inhibition in Ischemic Syndrome Management trial,¹⁸ in a subgroup analysis, had nearly identical findings. In the main part of this trial, patients with coronary artery disease and chest pain at rest or accelerating pain in the last 24 hours were randomized to receive tirofiban (Aggrastat) or heparin. Complete data on statin use were available for 1,616 (50%) of the 3,232 patients in this trial, and the rate of the primary end point (death, myocardial infarction, or recurrent ischemia) was analyzed on the basis of statin therapy in this subgroup.

Comment. Together, these data lead to the conclusion that, when admitted for either acute myocardial infarction or acute coronary syndrome, patients already receiving statins should not have them stopped, and those who had not been receiving statins should receive them immediately. The safety of these medications in the acute setting appears excellent: in the Myocardial Ischemia Reduction With Acute Cholesterol Lowering (MIRACL)¹² and the Pravastatin or Atorvastatin Evaluation and Infection Therapy (PROVE-IT)¹¹ trials, fewer than 5% of statin-treated patients had transient elevations in transaminase levels, and no cases of rhabdomyolysis were reported.

PERIOPERATIVE STATIN STUDIES

The data on perioperative statin use are mostly observational and retrospective and fall into essentially four surgical categories: coronary artery bypass grafting (CABG), carotid endarterectomy,^19,20 noncardiac vascular surgery, and major noncardiac surgery. Two meta-analyses have also evaluated the data.^21,22 The only randomized controlled trial (performed by Durazzo et al²³) was small and was carried out at a single center in vascular surgery patients, and the event rate was low.

Current recommendations from the National Cholesterol Education Program (NCEP)²⁴ say that patients who need CABG, have peripheral arterial disease, have an abdominal aortic aneurysm, or have cerebrovascular disease should already be on a statin to achieve an LDL-C goal level of less than 100 mg/dL, with an optional goal of less than 70 mg/dL, independent of surgery.

Since not all patients who should be on statins are actually on them, questions arise:

• Is it important (and safe) to start statin treatment preoperatively?
• Will patients with cardiovascular risk factors but without known cardiovascular disease benefit from statins perioperatively?

Noncardiac vascular surgery

Multiple retrospective studies have evaluated the effect of statins in patients undergoing major noncardiac vascular surgery.^25–32

Kertai et al²⁵ evaluated 570 patients in Holland who underwent elective open surgery for infrarenal abdominal aortic aneurysms between 1991 and 2001, looking for an association between statin use and the incidence of perioperative death from myocardial infarction. Only 162 of the 570 patients had been on long-term statin therapy before the surgery. The use of statins was only one of many known baseline characteristics that were significantly different between the two groups, including age, body mass index, known coronary artery disease, and use of angiotensin-converting enzyme inhibitors and beta-blockers. In univariate analysis, statins appeared to be protective: 6 (3.7%) of the patients in the statin group died of a myocardial infarction, compared with 45 (11%) of those in the nostatin group. A multivariate analysis yielded similar findings, with an odds ratio of 0.24 (95% CI 0.11–0.54).

Ward et al²⁷ performed a very similar retrospective study, with similar findings. In 446 patients who underwent surgery for infrarenal abdominal aortic aneurysm, statin therapy was associated with a significantly lower incidence of the combined end point of death, myocardial infarction, stroke, and major peripheral vascular complications, with an adjusted odds ratio of 0.36 (95% CI 0.14–0.93).

Poldermans et al²⁶ noted similar findings in a case-control study of noncardiac vascular surgery patients. Statin users had a much lower perioperative risk of death than did nonusers, with an adjusted odds ratio of 0.22 (95% CI 0.10–0.47).

O’Neil-Callahan et al,²⁸ in a cohort study, found that statin users had fewer perioperative cardiac complications, with an adjusted odds ratio of 0.49 (95% CI 0.28–0.84, P = .009).

Le Manach et al³³ reviewed the outcomes for all patients of a single hospital in Paris who underwent nonemergency infrarenal aortic procedures between January 2001 and December 2004. In January 2004, the hospital instituted guidelines to ensure that patients on statins continue taking them up to the evening before surgery and that statins be restarted on the first postoperative day (via nasogastric tube if necessary). Before 2004, there had been no specific guidelines, and patients on statins did not receive them for a median of 4 days postoperatively. Types of procedures were similar during the two time periods, as were the rates of beta-blocker use, preoperative revascularization, venous thromboembolism prophylaxis, and perioperative blood pressure control. After surgery, topononin I levels were measured in all patients as surveillance for cardiac events, and were defined as elevated when greater than 0.2 ng/mL.

Compared with patients not on statins at all, those treated with statins continuously throughout the perioperative period (after January 2004) had a lower rate of elevated troponin (relative risk 0.38). In contrast, those who had their statins transiently discontinued perioperatively (prior to 2004) had troponin elevations more often than those who had never been treated (relative risk 2.1). This suggested an over fivefold risk reduction (P < .001) conferred by not discontinuing statins in the immediate postoperative period. This finding was maintained after multivariate adjustment: statin withdrawal was associated with a 2.9-fold (95% CI 1.6–5.5) increase in the risk of cardiac enzyme elevations postoperatively. No fewer deaths were noted, but the study was not powered to detect a mortality difference.

Comment. Although secular trends cannot be entirely discounted as contributing to these findings, the prompt increase in cardiac events after just 4 days of statin withdrawal adds to the growing body of evidence suggesting that statin discontinuation can have harmful acute effects. It also brings up the question: Can starting statins benefit patients in the same time period?

Should statins be started before vascular surgery?

Schouten et al³² evaluated the effects of newly started or continued statin treatment in patients undergoing major elective vascular surgery. Patients were screened before surgery and started on statins if they were not already receiving them and their total cholesterol levels were elevated; new users received the medication for about 40 days before surgery. Of the 981 screened patients, 44 (5%) were newly started on statins and 182 (19%) were continued on their therapy. Perioperative death or myocardial infarction occurred in 22 (8.8%) of the statin users and 111 (14.7%) of the nonusers, a statistically significant difference. Temporary discontinuation (median 1 day) of statins in this study due to the inability to take an oral medication did not appear to affect the likelihood of a myocardial infarction.

Durazzo et al²³ performed a single-center, randomized, prospective, placebo-controlled, double-blind clinical trial of atorvastatin (Lipitor) 20 mg daily vs placebo in 100 patients undergoing noncardiac arterial vascular surgery. Patients were excluded if they had previously used medications to treat dyslipidemia, recently had a cardiovascular event, or had contraindications to statin treatment such as a baseline creatinine level greater than 2.0 mg/dL or severe hepatic disease. The intervention group received atorvastatin starting at least 2 weeks before surgery for a total of 45 days. Patients were then continued or started on a statin after surgery if their LDL-C level was greater than 100 mg/dL. Beta-blocker use was recommended “on the basis of current guidelines.”

One month after surgery, the LDL-C level was statistically significantly lower in the atorvastatin group. Since most patients did not continue or start statin therapy after the 45-day treatment period, the LDL-C levels were not statistically different at 3 and 6 months after surgery.

At 6 months, the rate of the primary end point (death from cardiovascular causes, nonfatal acute myocardial infarction, ischemic stroke, or unstable angina) was 26.0% in the placebo group and 8.0% in the atorvastatin group, a statistically significant difference. Three patients in the atorvastatin group had cardiac events in the first 10 days after surgery, compared with 11 patients in the placebo group. Thirteen of the 17 total cardiac events took place within 10 days after surgery.

One of the atorvastatin patients developed rhabdomyolysis and elevated aminotransferase levels.

Major noncardiac surgery

Lindenauer et al² performed a retrospective cohort study of surgical patients who were at least 18 years old and survived beyond the second hospital day. Patients were divided into a group receiving any form of lipid-lowering treatment (of whom more than 90% were taking statins) and a group that had never never received a lipid-lowering drug or only started one on the third day of the hospitalization or later. The period of study was from January 1, 2000, to December 31, 2001.

In all, 780,591 patients from 329 hospitals throughout the United States were included, of whom only 77,082 (9.9%) received lipid-lowering therapy. Eight percent of the patients underwent vascular surgery. Not surprisingly, the treated patients were more likely to have a history of hypertension, diabetes, ischemic heart disease, or hyperlipidemia. They also were more likely to have a vascular procedure performed, to have two or more cardiac risk factors (high-risk surgery, ischemic heart disease, congestive heart failure, cerebrovascular disease, renal insufficiency, or diabetes mellitus), and to be treated with beta-blockers and angiotensin-converting enzyme inhibitors, but they were less likely to have high-risk and emergency surgery performed.

The primary end point, perioperative death, occurred in 2.13% of the treated patients and 3.05% of the nontreated group. Compared with the rate in a propensity-matched cohort, the odds ratio adjusted for unbalanced covariates was 0.62 (95% CI 0.58–0.67) in favor of lipid treatment. Stratification by cardiac risk index revealed a number needed to treat of 186 for those with no risk factors, 60 for those with two risk factors, and 30 for those with four or more risk factors.

Unfortunately, this analysis was not able to take into account whether and for how long patients were receiving lipid-lowering therapy before hospitalization. It therefore does not answer the questions of whether starting lipid-lowering therapy before surgery is beneficial or whether stopping it is harmful. It also does not shed light on whether perioperative lipid-lowering increases the risk of rhabdomyolysis or liver disease.

Two recent retrospective cohort studies evaluated the outcomes in patients undergoing carotid endarterectomy.^19,20

Kennedy et al¹⁹ found that patients on a statin at the time of admission who had symptomatic carotid disease had lower rates of inhospital death (adjusted odds ratio 0.24, 95% CI 0.06–0.91) and ischemic stroke or death (adjusted odds ratio 0.55, 95% CI 0.31–0.97). However, cardiac outcomes among these symptomatic patients were not significantly improved (odds ratio 0.82, 95% CI 0.45–1.50), nor was there benefit for asymptomatic patients, raising the possibility that the positive findings were due to chance or that patients at lower baseline risk for vascular events may have less benefit.

McGirt et al²⁰ performed a similar study; they did not, however, distinguish whether patients had symptomatic vs asymptomatic carotid disease. The 30-day risk of perioperative stroke was lower in patients treated with a statin, with an odds ratio of 0.41 (95% CI 0.18–0.93); the odds ratio for death was 0.21 (95% CI 0.05–0.96). Cardiac outcomes were not significantly affected.

Coronary artery bypass graft surgery

According to the NCEP recommendations, nearly all patients undergoing CABG should already be on a statin before surgery since they all have known coronary artery disease. Multiple observational studies have offered confirmatory evidence that statins are beneficial in this setting.^34–38

Liakopoulos et al³⁹ evaluated whether the anti-inflammatory effects of statins may, in part, account for their beneficial effect in the perioperative period. The authors prospectively matched 18 patients who were taking statins and were referred for elective CABG with 18 patients who were not prescribed statins previously. The only major measured baseline characteristic that differed between the two groups was a statistically significantly lower LDL-C level in the statin group. The operative characteristics did not differ, and cytokine levels at baseline were similar.

Tumor necrosis factor alpha levels increased significantly in the control group but did not change significantly in the statin group. Interleukin 8 increased in both groups by a similar amount. Interleukin 6 (the major inducer of C-reactive protein) increased from baseline in both groups but did not increase nearly as much in the statin group as in the control group; the intergroup difference was statistically significant. The anti-inflammatory cytokine interleukin 10 increased minimally from baseline in the control group, while the statin group’s levels increased significantly above baseline and those of the control group.

Christenson⁴⁰ also found that inflammatory markers were improved with pre-CABG statin treatment in a small randomized trial in which patients received simvastatin 20 mg 4 weeks prior to CABG surgery vs no statin. Interestingly, far fewer statin-treated patients developed thrombocytosis (platelet count > 400 × 10⁹/L) than did control patients (3% vs 81%, P < .0001).

RISKS OF PERIOPERATIVE STATINS

The risks associated with statin therapy in general appear low, but specific perioperative risks have not been well studied.

Baigent et al,⁴¹ in a meta-analysis of randomized trials of nonperioperative statin therapy, found that rhabdomyolysis occurred in 9 (0.023%) of 39,884 patients receiving statins vs 6 (0.015%) of the 39,817 controls, with a number needed to harm of 12,500. Moreover, the rates of nonvascular death and cancer did not increase. It is plausible that the risk is somewhat greater in the perioperative setting but is likely not enough to outweigh the potential benefits, especially since the risk of ischemic vascular events is particularly high then.

Some of the perioperative studies cited above specifically addressed potential risks. For example, in the study by Schouten et al,³² mild creatine kinase elevations were more common in the statin-treated group, but the incidence of moderate and severe creatine kinase elevations did not differ significantly. No case of rhabdomyolysis occurred, and length of surgery was the only predictor of myopathy. MIRACL and PROVE-IT revealed similar safety profiles; aminotransferase levels normalized when statins were stopped, and no cases of rhabdomyolysis occurred.^11,12 In the vascular surgery study by Durazzo et al,²³ 1 (2%) of the 50 atorvastatin-treated patients developed both rhabdomyolysis and elevated aminotransferase levels that prompted discontinuation of the statin.

Overall, the observational studies do not indicate that statin continuation or treatment is harmful in perioperative patients. However, these studies did not specifically evaluate patients with acute insults from surgery such as sepsis, renal failure, or hepatitis. It is unknown what effect statin therapy would have in those patients and whether statins should be selectively discontinued in patients who develop major hepatic, musculoskeletal, or renal complications after surgery.

OUR RECOMMENDATIONS

Before CABG or vascular surgery

Given the NCEP recommendations, existing primary and secondary prevention studies, observational studies of CABG and noncardiac vascular surgery patients, and the one randomized trial of vascular surgery patients, data support the use of statins in nearly all patients undergoing cardiac or vascular surgery. We advocate starting statins in the perioperative period to take advantage of their rapid-acting pleiotropic effects, and continuing them long-term to take advantage of their lipid-lowering effects. This recommendation is in line with the recently released American College of Cardiology/American Heart Association (ACC/AHA) 2007 perioperative guidelines that state “for patients undergoing vascular surgery with or without clinical risk factors, statin use is reasonable.”⁴²

Although the ideal time to start statins is not certain, the study by Durazzo et al²³ suggests that they should be started at least 2 weeks before surgery if possible. Moreover, patients already taking statins should definitely not have their statins discontinued if at all possible.

Before major nonvascular surgery

For patients undergoing major nonvascular (intermediate-risk) surgery, physicians should first ascertain if the patient has an indication for statin therapy based on current nonsurgical lipid level recommendations. However, even if there is no clear indication for statin therapy based on NCEP guidelines, we endorse the recently released ACC/AHA perioperative guidelines that state that statin therapy can be considered in patients with a risk factor who are undergoing intermediate-risk procedures. Moreover, we wholeheartedly support the ACC/AHA’s strongest recommendation that patients who are already receiving statins and are undergoing noncardiac surgery should not have their statins discontinued.

When to discontinue statins?

The risk of harm overall appears to be minimal and certainly less than the likelihood of benefit. It is reasonable to observe patients postoperatively for adverse clinical events that may increase the risk of perioperative statin treatment, such as acute renal failure, hepatic failure, or sepsis, but whether statins should be stopped in patients with these complications remains unknown; we advocate individualizing the decision.

More studies needed

We need more data on whether moderate-risk patients undergoing moderate-risk surgery benefit from perioperative statin therapy, when therapy should be started, whether therapy should be started on the day of surgery if it was not started earlier, which statin and what doses are optimal, how long therapy should be continued, and what degree of risk is associated with perioperative statin therapy.

Fortunately, important data should be forthcoming in the next few years: the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE-IV) study⁴³ is a 4-year two-by-two factorial placebo-controlled study evaluating the use of fluvastatin (Lescol) and bisoprolol (Zebeta, a beta-blocker) separately and together in patients who are older than 40 years, are undergoing elective noncardiac surgery, have an estimated risk of cardiovascular death of more than 1%, have not used statins previously, and do not have elevated cholesterol.