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Anticoagulant therapy for AFib in patients with end-stage renal disease
Warfarin or apixaban are sensible options
Case
A 78-year-old woman with end-stage renal disease (ESRD) is hospitalized with cellulitis and is incidentally found to be in atrial fibrillation. She does not have a history of mitral stenosis, nor does she have a prosthetic valve. She does have a history of hypertension, diabetes, and prior stroke without residual deficits.
After counseling her about the risk of stroke associated with atrial fibrillation (AFib) she makes it clear she is interested in pharmacologic therapy to minimize her risk of stroke and asks what medication you would recommend for anticoagulation.
Brief overview of the issue
Anticoagulation for AFib is indicated for stroke prophylaxis in patients with an elevated risk of stroke. The CHA2DS2-VASc score is useful in calculating an individual patient’s risk of stroke and as a decision tool to determine who would benefit from anticoagulation, and it is recommended in the American Heart Association guidelines.1
Low-risk patients (CHA2DS2-VASc score of 0 in men or 1 in women) should not be started on anticoagulation for stroke prophylaxis. For anyone with a risk factor, other than being female, anticoagulation is indicated and should be considered.
The guideline recommends anticoagulant therapy, not antiplatelet agents. For most of the recent past, this has meant a vitamin K antagonist (warfarin) or sometimes a low-molecular-weight heparin injected subcutaneously. Over the past decade, however, with the approval of multiple direct oral anticoagulants (DOACs), nonwarfarin oral anticoagulation has grown in popularity as the prophylactic medication of choice.2
While the data for patients with preserved renal function is robust, there is far less data to guide decision making for patients with end-stage renal disease.
Overview of the data
Until the introduction of DOACs, warfarin was the main agent used for stroke prophylaxis in patients with end-stage kidney disease and AFib. Professional guidelines favored warfarin for these patients who were mostly excluded from DOAC trials. Specialized conferences also looked at this issue.
The Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference, which reviewed chronic kidney disease and arrhythmias, noted that there were no randomized controlled trials that examined the efficacy and safety of anticoagulation in chronic kidney disease patients with estimated creatinine clearance less than 30 mL/min. They remarked that there was insufficient high-quality evidence to recommend warfarin for the prevention of stroke in patients with AFib and dialysis-dependent chronic kidney disease.
Since, according to other trials, DOACs had better safety profiles in other populations, the conference noted that lower-dose apixaban (2.5 mg orally twice daily) or rivaroxaban (15 mg daily) may be considered in this population until clinical safety data were available. Furthermore, the conference recommended that these patients be treated with a multidisciplinary approach in regards to anticoagulation and have an annual reevaluation of treatment goals, along with a risk-benefit assessment.3
Since the publication of the 2018 AHA guidelines and the guidance document that resulted from the KDIGO conference, additional research has been published comparing anticoagulation with a DOAC versus warfarin for AFib in patients with ESRD.
“Outcomes associated with apixaban use in patients with end-stage kidney disease and atrial fibrillation in the United States” was an observational, retrospective, cohort study that compared outcomes in dialysis patients who took warfarin for AFib with those who took apixaban.4 Patients’ data was taken from the U.S. Renal Data System database and were included in the final analysis if they had ESRD, a recent diagnosis of AFib or atrial flutter, and a new prescription for either warfarin or apixaban. Outcome measures were stroke or systemic embolism, major bleeding (critical site, transfusion, or death), gastrointestinal bleeding, intracranial bleeding, or death. Drug usage and compliance were assessed using Medicare Part D prescription information.
A total of 25,523 patients met the inclusion/exclusion criteria and had taken either warfarin (n = 23,172) or apixaban (n = 2,351). To account for selection bias in these cohorts, a subset of the warfarin patients was selected based on prognostic score matching. The prognostic score was calculated from the baseline characteristics (which included age, stroke history, diabetes, smoking, antiplatelet medication, liver disease, prior bleeding, and CHA2DS2-VASc score). Kaplan-Meier and Cox regression analysis were used to give hazard ratios and 95% confidence intervals for each outcome measure. Prespecified subgroup analyses were conducted to compare apixaban doses, where 44% were prescribed 5 mg b.i.d. and 56% were prescribed 2.5 mg b.i.d..
In the study, patients in the apixaban group had a significantly lower risk of major bleeding as compared with the warfarin group (HR, 0.72; 95% CI, 0.59-0.87; P less than .001) with overall high rates of major bleeding in both groups at 19.7 and 22.9 per 100 patient-years in the apixaban group and warfarin group, respectively. There was no difference in the rate of stroke/systemic embolism between patients receiving apixaban and warfarin (HR, 0.88; 95% CI, 0.69-1.12; P = .29). There was a nonsignificant trend toward decreased risk of GI bleeding in the apixaban group and no significant differences between the groups in the rates of intracranial bleeding. Apixaban was also associated with a nonsignificant trend toward lower risk of mortality (HR, 0.85; 95% CI, 0.71-1.01; P = .06).
Notably, censoring rates because of expired prescriptions or a 1-month gap between prescriptions were high in both groups and the majority of censoring occurred within the first 12 months. Additionally, in dose specific analyses, patients receiving the 5-mg, twice-daily dose were found to have statistically significant decreases in risk of stroke/systemic embolism (P = .035) and mortality (P = .005) as compared with the 2.5-mg, twice-daily dose without significant differences in GI or intracranial bleeding.
There are three ongoing, open-label, randomized, controlled trials examining anticoagulation for nonvalvular AFib in patients with ESRD on hemodialysis with two comparing apixaban to warfarin (or derivative) and the other warfarin versus no anticoagulation.5 All trials are in adult patients with documented AFib and CHA2DS2-VASc score of at least 2. AKADIA (Germany based) plans to enroll 222 patients and compares a vitamin K antagonist (INR goal, 2-3) with 2.5-mg b.i.d. apixaban patients with ESRD on hemodialysis for at least 3 months with primary outcome of major and clinically relevant nonmajor bleeding and secondary outcome of thromboembolic events, as well as apixaban levels pre- and post hemodialysis.
RENAL-AF (U.S. based) plans to enrolled 762 patients and compares 5-mg b.i.d. apixaban (with 2.5 mg for selected patients) with warfarin in people of chronic hemodialysis with primary outcome of days to first major or clinically relevant nonmajor bleeding event and secondary outcome of stroke, systemic embolism, mortality, adherence and plasma apixaban levels. AVKDIAL (France based) plans to enroll 855 patients and compares no anticoagulation with vitamin K antagonists in patients on hemodialysis for at least 1 month, with primary outcome of cumulative incidence of severe bleeding and thrombosis.
Application of the data to our original case
Our patient is Medicare age with ESRD and newly diagnosed nonvalvular AFib. Recent data suggests apixaban could be used for stroke prevention instead of the prior standard of care, warfarin. This approach is supported in the 2019 guidelines.1
Patients with ESRD have an increased risk of bleeding and apixaban was shown to have less bleeding complications than warfarin in this analysis. However, only standard-dose apixaban was associated with a statistically significant lower risk of stroke/systemic embolism, major bleeding, and death. Reduced-dose apixaban had a lower risk of major bleeding but no difference for stroke/systemic embolism or death. Reduced-dose apixaban is used for patients who have two out of the following three criteria: aged at least 80 years, weight of at least 60 kg, and creatinine of at least 1.5 mg/dL. Therefore, many Medicare-age patients with ESRD would not be indicated for the dose of apixaban that was shown to improve the most important outcomes of stroke/SE and death.
It may still be beneficial to use apixaban in this patient since it appears to work as well as warfarin for stroke/systemic embolism prevention with less bleeding complications.
Bottom line
For patients who have decided to pursue an anticoagulation strategy for stroke prevention in AFib and have end-stage renal disease, either warfarin or apixaban are sensible options.
Dr. Farber is a medical instructor at Duke University Health System in Durham, N.C. Dr. Stafford is a medical instructor at Duke University. Dr. Sata is assistant professor of medicine at Duke University. Dr. Abdo and Dr. Menon are hospitalists at Duke University. Dr. Brooks is assistant professor of medicine at Duke University. Dr. Wachter is associate medical director at Duke Regional Hospital and assistant professor of medicine at Duke University. Dr. Sharma is associate medical director for clinical education in hospital medicine at Duke Regional Hospital and assistant professor of medicine at Duke University.
References
1. January CT et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;139. doi: 1161/CIR.0000000000000665.
2. Lippi G et al. Direct oral anticoagulants: Analysis of worldwide use and popularity using Google Trends. Ann Transl Med. 2017 Aug; 5(16):322. doi: 10.21037/atm.2017.06.65.
3. Turakhia MP et al. Chronic kidney disease and arrhythmias: Conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Eur Heart J. 2018 Jun 21;39(24):2314-25. doi: 10.1093/eurheartj/ehy060.
4. Siontis KC et al. Outcomes associated with apixaban use in patients with end-stage kidney disease and atrial fibrillation in the United States. Circulation. 2018 Oct 9;138(15):1519-29. doi: 10.1161/CIRCULATIONAHA.118.035418.
5. Nigwekar SU et al. Long-term anticoagulation for patient receiving dialysis: Tilting the benefit-to-risk ratio? Circulation. 2018 Oct 9;138(15):1530-3. doi: 10.1161/CIRCULATIONAHA.118.037091.
Key points
- According to 2019 American Heart Association guidelines, warfarin or apixaban are reasonable options for stroke prevention for patients who have end-stage renal disease and who plan for anticoagulation because of atrial fibrillation.
- Recent observational data suggests that apixaban may be safer than warfarin in this population.
- Several randomized, controlled trials are ongoing that may help determine the optimal agent to use in this setting.
- Until more definitive data is available, a reasonable approach is to discuss the risks and benefits of various treatment strategies with patients, and engage a multidisciplinary team (cardiologist, nephrologist, primary care provider, pharmacist) in the decision making process.
Additional reading
January CT et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;139. doi: 1161/CIR.0000000000000665.
Nigwekar SU et al. Long-term anticoagulation for patient receiving dialysis: Tilting the benefit to risk ratio? Circulation. 2018 Oct 9;138(15):1530-3. doi: 10.1161/CIRCULATIONAHA.118.037091.
Garlo KG et al. Demystifying the benefits and harms of anticoagulation for atrial fibrillation in chronic kidney disease. Clin J Am Soc Nephrol 2019;14:125-36. doi: 10.2215/CJN.06430518.
Quiz
Two days ago you admitted a 72-year-old woman with end-stage renal disease on dialysis who had developed new-onset atrial fibrillation causing a mild acute diastolic congestive heart failure exacerbation. Transthoracic ECG showed a preserved left ventricular ejection fraction and no significant valvular disease. After two sessions of dialysis in the hospital and initiation of a beta-blocker for control of her heart rate, she is stable and ready for discharge. Her discharge weight is 75 kg.
Which of the following recommendations should you make to this patient regarding anticoagulation for prevention of stroke and systemic embolism from atrial fibrillation?
A. Take warfarin with a international normalized ratio goal of 2.5.
B. Take apixaban 2.5 mg twice a day.
C. Take apixaban 5 mg twice a day.
D. Discuss the risks/benefits of various treatment approaches with the patient, and involve the hospital pharmacist as well as the patient’s nephrologist, cardiologist, and/or primary care provider in the decision making process to reach a consensus and to ensure a safe follow-up plan.
The best answer is D. While A, B, and C are all reasonable approaches based on the available data and current guidelines, the best approach is to involve the patient and the multidisciplinary team in the decision making process. When more clinical trial data becomes available in the future, the optimal approach to managing patients such as this one may become clearer, but until then it makes sense to take into account individual patient characteristics and patient preferences.
Warfarin or apixaban are sensible options
Warfarin or apixaban are sensible options
Case
A 78-year-old woman with end-stage renal disease (ESRD) is hospitalized with cellulitis and is incidentally found to be in atrial fibrillation. She does not have a history of mitral stenosis, nor does she have a prosthetic valve. She does have a history of hypertension, diabetes, and prior stroke without residual deficits.
After counseling her about the risk of stroke associated with atrial fibrillation (AFib) she makes it clear she is interested in pharmacologic therapy to minimize her risk of stroke and asks what medication you would recommend for anticoagulation.
Brief overview of the issue
Anticoagulation for AFib is indicated for stroke prophylaxis in patients with an elevated risk of stroke. The CHA2DS2-VASc score is useful in calculating an individual patient’s risk of stroke and as a decision tool to determine who would benefit from anticoagulation, and it is recommended in the American Heart Association guidelines.1
Low-risk patients (CHA2DS2-VASc score of 0 in men or 1 in women) should not be started on anticoagulation for stroke prophylaxis. For anyone with a risk factor, other than being female, anticoagulation is indicated and should be considered.
The guideline recommends anticoagulant therapy, not antiplatelet agents. For most of the recent past, this has meant a vitamin K antagonist (warfarin) or sometimes a low-molecular-weight heparin injected subcutaneously. Over the past decade, however, with the approval of multiple direct oral anticoagulants (DOACs), nonwarfarin oral anticoagulation has grown in popularity as the prophylactic medication of choice.2
While the data for patients with preserved renal function is robust, there is far less data to guide decision making for patients with end-stage renal disease.
Overview of the data
Until the introduction of DOACs, warfarin was the main agent used for stroke prophylaxis in patients with end-stage kidney disease and AFib. Professional guidelines favored warfarin for these patients who were mostly excluded from DOAC trials. Specialized conferences also looked at this issue.
The Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference, which reviewed chronic kidney disease and arrhythmias, noted that there were no randomized controlled trials that examined the efficacy and safety of anticoagulation in chronic kidney disease patients with estimated creatinine clearance less than 30 mL/min. They remarked that there was insufficient high-quality evidence to recommend warfarin for the prevention of stroke in patients with AFib and dialysis-dependent chronic kidney disease.
Since, according to other trials, DOACs had better safety profiles in other populations, the conference noted that lower-dose apixaban (2.5 mg orally twice daily) or rivaroxaban (15 mg daily) may be considered in this population until clinical safety data were available. Furthermore, the conference recommended that these patients be treated with a multidisciplinary approach in regards to anticoagulation and have an annual reevaluation of treatment goals, along with a risk-benefit assessment.3
Since the publication of the 2018 AHA guidelines and the guidance document that resulted from the KDIGO conference, additional research has been published comparing anticoagulation with a DOAC versus warfarin for AFib in patients with ESRD.
“Outcomes associated with apixaban use in patients with end-stage kidney disease and atrial fibrillation in the United States” was an observational, retrospective, cohort study that compared outcomes in dialysis patients who took warfarin for AFib with those who took apixaban.4 Patients’ data was taken from the U.S. Renal Data System database and were included in the final analysis if they had ESRD, a recent diagnosis of AFib or atrial flutter, and a new prescription for either warfarin or apixaban. Outcome measures were stroke or systemic embolism, major bleeding (critical site, transfusion, or death), gastrointestinal bleeding, intracranial bleeding, or death. Drug usage and compliance were assessed using Medicare Part D prescription information.
A total of 25,523 patients met the inclusion/exclusion criteria and had taken either warfarin (n = 23,172) or apixaban (n = 2,351). To account for selection bias in these cohorts, a subset of the warfarin patients was selected based on prognostic score matching. The prognostic score was calculated from the baseline characteristics (which included age, stroke history, diabetes, smoking, antiplatelet medication, liver disease, prior bleeding, and CHA2DS2-VASc score). Kaplan-Meier and Cox regression analysis were used to give hazard ratios and 95% confidence intervals for each outcome measure. Prespecified subgroup analyses were conducted to compare apixaban doses, where 44% were prescribed 5 mg b.i.d. and 56% were prescribed 2.5 mg b.i.d..
In the study, patients in the apixaban group had a significantly lower risk of major bleeding as compared with the warfarin group (HR, 0.72; 95% CI, 0.59-0.87; P less than .001) with overall high rates of major bleeding in both groups at 19.7 and 22.9 per 100 patient-years in the apixaban group and warfarin group, respectively. There was no difference in the rate of stroke/systemic embolism between patients receiving apixaban and warfarin (HR, 0.88; 95% CI, 0.69-1.12; P = .29). There was a nonsignificant trend toward decreased risk of GI bleeding in the apixaban group and no significant differences between the groups in the rates of intracranial bleeding. Apixaban was also associated with a nonsignificant trend toward lower risk of mortality (HR, 0.85; 95% CI, 0.71-1.01; P = .06).
Notably, censoring rates because of expired prescriptions or a 1-month gap between prescriptions were high in both groups and the majority of censoring occurred within the first 12 months. Additionally, in dose specific analyses, patients receiving the 5-mg, twice-daily dose were found to have statistically significant decreases in risk of stroke/systemic embolism (P = .035) and mortality (P = .005) as compared with the 2.5-mg, twice-daily dose without significant differences in GI or intracranial bleeding.
There are three ongoing, open-label, randomized, controlled trials examining anticoagulation for nonvalvular AFib in patients with ESRD on hemodialysis with two comparing apixaban to warfarin (or derivative) and the other warfarin versus no anticoagulation.5 All trials are in adult patients with documented AFib and CHA2DS2-VASc score of at least 2. AKADIA (Germany based) plans to enroll 222 patients and compares a vitamin K antagonist (INR goal, 2-3) with 2.5-mg b.i.d. apixaban patients with ESRD on hemodialysis for at least 3 months with primary outcome of major and clinically relevant nonmajor bleeding and secondary outcome of thromboembolic events, as well as apixaban levels pre- and post hemodialysis.
RENAL-AF (U.S. based) plans to enrolled 762 patients and compares 5-mg b.i.d. apixaban (with 2.5 mg for selected patients) with warfarin in people of chronic hemodialysis with primary outcome of days to first major or clinically relevant nonmajor bleeding event and secondary outcome of stroke, systemic embolism, mortality, adherence and plasma apixaban levels. AVKDIAL (France based) plans to enroll 855 patients and compares no anticoagulation with vitamin K antagonists in patients on hemodialysis for at least 1 month, with primary outcome of cumulative incidence of severe bleeding and thrombosis.
Application of the data to our original case
Our patient is Medicare age with ESRD and newly diagnosed nonvalvular AFib. Recent data suggests apixaban could be used for stroke prevention instead of the prior standard of care, warfarin. This approach is supported in the 2019 guidelines.1
Patients with ESRD have an increased risk of bleeding and apixaban was shown to have less bleeding complications than warfarin in this analysis. However, only standard-dose apixaban was associated with a statistically significant lower risk of stroke/systemic embolism, major bleeding, and death. Reduced-dose apixaban had a lower risk of major bleeding but no difference for stroke/systemic embolism or death. Reduced-dose apixaban is used for patients who have two out of the following three criteria: aged at least 80 years, weight of at least 60 kg, and creatinine of at least 1.5 mg/dL. Therefore, many Medicare-age patients with ESRD would not be indicated for the dose of apixaban that was shown to improve the most important outcomes of stroke/SE and death.
It may still be beneficial to use apixaban in this patient since it appears to work as well as warfarin for stroke/systemic embolism prevention with less bleeding complications.
Bottom line
For patients who have decided to pursue an anticoagulation strategy for stroke prevention in AFib and have end-stage renal disease, either warfarin or apixaban are sensible options.
Dr. Farber is a medical instructor at Duke University Health System in Durham, N.C. Dr. Stafford is a medical instructor at Duke University. Dr. Sata is assistant professor of medicine at Duke University. Dr. Abdo and Dr. Menon are hospitalists at Duke University. Dr. Brooks is assistant professor of medicine at Duke University. Dr. Wachter is associate medical director at Duke Regional Hospital and assistant professor of medicine at Duke University. Dr. Sharma is associate medical director for clinical education in hospital medicine at Duke Regional Hospital and assistant professor of medicine at Duke University.
References
1. January CT et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;139. doi: 1161/CIR.0000000000000665.
2. Lippi G et al. Direct oral anticoagulants: Analysis of worldwide use and popularity using Google Trends. Ann Transl Med. 2017 Aug; 5(16):322. doi: 10.21037/atm.2017.06.65.
3. Turakhia MP et al. Chronic kidney disease and arrhythmias: Conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Eur Heart J. 2018 Jun 21;39(24):2314-25. doi: 10.1093/eurheartj/ehy060.
4. Siontis KC et al. Outcomes associated with apixaban use in patients with end-stage kidney disease and atrial fibrillation in the United States. Circulation. 2018 Oct 9;138(15):1519-29. doi: 10.1161/CIRCULATIONAHA.118.035418.
5. Nigwekar SU et al. Long-term anticoagulation for patient receiving dialysis: Tilting the benefit-to-risk ratio? Circulation. 2018 Oct 9;138(15):1530-3. doi: 10.1161/CIRCULATIONAHA.118.037091.
Key points
- According to 2019 American Heart Association guidelines, warfarin or apixaban are reasonable options for stroke prevention for patients who have end-stage renal disease and who plan for anticoagulation because of atrial fibrillation.
- Recent observational data suggests that apixaban may be safer than warfarin in this population.
- Several randomized, controlled trials are ongoing that may help determine the optimal agent to use in this setting.
- Until more definitive data is available, a reasonable approach is to discuss the risks and benefits of various treatment strategies with patients, and engage a multidisciplinary team (cardiologist, nephrologist, primary care provider, pharmacist) in the decision making process.
Additional reading
January CT et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;139. doi: 1161/CIR.0000000000000665.
Nigwekar SU et al. Long-term anticoagulation for patient receiving dialysis: Tilting the benefit to risk ratio? Circulation. 2018 Oct 9;138(15):1530-3. doi: 10.1161/CIRCULATIONAHA.118.037091.
Garlo KG et al. Demystifying the benefits and harms of anticoagulation for atrial fibrillation in chronic kidney disease. Clin J Am Soc Nephrol 2019;14:125-36. doi: 10.2215/CJN.06430518.
Quiz
Two days ago you admitted a 72-year-old woman with end-stage renal disease on dialysis who had developed new-onset atrial fibrillation causing a mild acute diastolic congestive heart failure exacerbation. Transthoracic ECG showed a preserved left ventricular ejection fraction and no significant valvular disease. After two sessions of dialysis in the hospital and initiation of a beta-blocker for control of her heart rate, she is stable and ready for discharge. Her discharge weight is 75 kg.
Which of the following recommendations should you make to this patient regarding anticoagulation for prevention of stroke and systemic embolism from atrial fibrillation?
A. Take warfarin with a international normalized ratio goal of 2.5.
B. Take apixaban 2.5 mg twice a day.
C. Take apixaban 5 mg twice a day.
D. Discuss the risks/benefits of various treatment approaches with the patient, and involve the hospital pharmacist as well as the patient’s nephrologist, cardiologist, and/or primary care provider in the decision making process to reach a consensus and to ensure a safe follow-up plan.
The best answer is D. While A, B, and C are all reasonable approaches based on the available data and current guidelines, the best approach is to involve the patient and the multidisciplinary team in the decision making process. When more clinical trial data becomes available in the future, the optimal approach to managing patients such as this one may become clearer, but until then it makes sense to take into account individual patient characteristics and patient preferences.
Case
A 78-year-old woman with end-stage renal disease (ESRD) is hospitalized with cellulitis and is incidentally found to be in atrial fibrillation. She does not have a history of mitral stenosis, nor does she have a prosthetic valve. She does have a history of hypertension, diabetes, and prior stroke without residual deficits.
After counseling her about the risk of stroke associated with atrial fibrillation (AFib) she makes it clear she is interested in pharmacologic therapy to minimize her risk of stroke and asks what medication you would recommend for anticoagulation.
Brief overview of the issue
Anticoagulation for AFib is indicated for stroke prophylaxis in patients with an elevated risk of stroke. The CHA2DS2-VASc score is useful in calculating an individual patient’s risk of stroke and as a decision tool to determine who would benefit from anticoagulation, and it is recommended in the American Heart Association guidelines.1
Low-risk patients (CHA2DS2-VASc score of 0 in men or 1 in women) should not be started on anticoagulation for stroke prophylaxis. For anyone with a risk factor, other than being female, anticoagulation is indicated and should be considered.
The guideline recommends anticoagulant therapy, not antiplatelet agents. For most of the recent past, this has meant a vitamin K antagonist (warfarin) or sometimes a low-molecular-weight heparin injected subcutaneously. Over the past decade, however, with the approval of multiple direct oral anticoagulants (DOACs), nonwarfarin oral anticoagulation has grown in popularity as the prophylactic medication of choice.2
While the data for patients with preserved renal function is robust, there is far less data to guide decision making for patients with end-stage renal disease.
Overview of the data
Until the introduction of DOACs, warfarin was the main agent used for stroke prophylaxis in patients with end-stage kidney disease and AFib. Professional guidelines favored warfarin for these patients who were mostly excluded from DOAC trials. Specialized conferences also looked at this issue.
The Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference, which reviewed chronic kidney disease and arrhythmias, noted that there were no randomized controlled trials that examined the efficacy and safety of anticoagulation in chronic kidney disease patients with estimated creatinine clearance less than 30 mL/min. They remarked that there was insufficient high-quality evidence to recommend warfarin for the prevention of stroke in patients with AFib and dialysis-dependent chronic kidney disease.
Since, according to other trials, DOACs had better safety profiles in other populations, the conference noted that lower-dose apixaban (2.5 mg orally twice daily) or rivaroxaban (15 mg daily) may be considered in this population until clinical safety data were available. Furthermore, the conference recommended that these patients be treated with a multidisciplinary approach in regards to anticoagulation and have an annual reevaluation of treatment goals, along with a risk-benefit assessment.3
Since the publication of the 2018 AHA guidelines and the guidance document that resulted from the KDIGO conference, additional research has been published comparing anticoagulation with a DOAC versus warfarin for AFib in patients with ESRD.
“Outcomes associated with apixaban use in patients with end-stage kidney disease and atrial fibrillation in the United States” was an observational, retrospective, cohort study that compared outcomes in dialysis patients who took warfarin for AFib with those who took apixaban.4 Patients’ data was taken from the U.S. Renal Data System database and were included in the final analysis if they had ESRD, a recent diagnosis of AFib or atrial flutter, and a new prescription for either warfarin or apixaban. Outcome measures were stroke or systemic embolism, major bleeding (critical site, transfusion, or death), gastrointestinal bleeding, intracranial bleeding, or death. Drug usage and compliance were assessed using Medicare Part D prescription information.
A total of 25,523 patients met the inclusion/exclusion criteria and had taken either warfarin (n = 23,172) or apixaban (n = 2,351). To account for selection bias in these cohorts, a subset of the warfarin patients was selected based on prognostic score matching. The prognostic score was calculated from the baseline characteristics (which included age, stroke history, diabetes, smoking, antiplatelet medication, liver disease, prior bleeding, and CHA2DS2-VASc score). Kaplan-Meier and Cox regression analysis were used to give hazard ratios and 95% confidence intervals for each outcome measure. Prespecified subgroup analyses were conducted to compare apixaban doses, where 44% were prescribed 5 mg b.i.d. and 56% were prescribed 2.5 mg b.i.d..
In the study, patients in the apixaban group had a significantly lower risk of major bleeding as compared with the warfarin group (HR, 0.72; 95% CI, 0.59-0.87; P less than .001) with overall high rates of major bleeding in both groups at 19.7 and 22.9 per 100 patient-years in the apixaban group and warfarin group, respectively. There was no difference in the rate of stroke/systemic embolism between patients receiving apixaban and warfarin (HR, 0.88; 95% CI, 0.69-1.12; P = .29). There was a nonsignificant trend toward decreased risk of GI bleeding in the apixaban group and no significant differences between the groups in the rates of intracranial bleeding. Apixaban was also associated with a nonsignificant trend toward lower risk of mortality (HR, 0.85; 95% CI, 0.71-1.01; P = .06).
Notably, censoring rates because of expired prescriptions or a 1-month gap between prescriptions were high in both groups and the majority of censoring occurred within the first 12 months. Additionally, in dose specific analyses, patients receiving the 5-mg, twice-daily dose were found to have statistically significant decreases in risk of stroke/systemic embolism (P = .035) and mortality (P = .005) as compared with the 2.5-mg, twice-daily dose without significant differences in GI or intracranial bleeding.
There are three ongoing, open-label, randomized, controlled trials examining anticoagulation for nonvalvular AFib in patients with ESRD on hemodialysis with two comparing apixaban to warfarin (or derivative) and the other warfarin versus no anticoagulation.5 All trials are in adult patients with documented AFib and CHA2DS2-VASc score of at least 2. AKADIA (Germany based) plans to enroll 222 patients and compares a vitamin K antagonist (INR goal, 2-3) with 2.5-mg b.i.d. apixaban patients with ESRD on hemodialysis for at least 3 months with primary outcome of major and clinically relevant nonmajor bleeding and secondary outcome of thromboembolic events, as well as apixaban levels pre- and post hemodialysis.
RENAL-AF (U.S. based) plans to enrolled 762 patients and compares 5-mg b.i.d. apixaban (with 2.5 mg for selected patients) with warfarin in people of chronic hemodialysis with primary outcome of days to first major or clinically relevant nonmajor bleeding event and secondary outcome of stroke, systemic embolism, mortality, adherence and plasma apixaban levels. AVKDIAL (France based) plans to enroll 855 patients and compares no anticoagulation with vitamin K antagonists in patients on hemodialysis for at least 1 month, with primary outcome of cumulative incidence of severe bleeding and thrombosis.
Application of the data to our original case
Our patient is Medicare age with ESRD and newly diagnosed nonvalvular AFib. Recent data suggests apixaban could be used for stroke prevention instead of the prior standard of care, warfarin. This approach is supported in the 2019 guidelines.1
Patients with ESRD have an increased risk of bleeding and apixaban was shown to have less bleeding complications than warfarin in this analysis. However, only standard-dose apixaban was associated with a statistically significant lower risk of stroke/systemic embolism, major bleeding, and death. Reduced-dose apixaban had a lower risk of major bleeding but no difference for stroke/systemic embolism or death. Reduced-dose apixaban is used for patients who have two out of the following three criteria: aged at least 80 years, weight of at least 60 kg, and creatinine of at least 1.5 mg/dL. Therefore, many Medicare-age patients with ESRD would not be indicated for the dose of apixaban that was shown to improve the most important outcomes of stroke/SE and death.
It may still be beneficial to use apixaban in this patient since it appears to work as well as warfarin for stroke/systemic embolism prevention with less bleeding complications.
Bottom line
For patients who have decided to pursue an anticoagulation strategy for stroke prevention in AFib and have end-stage renal disease, either warfarin or apixaban are sensible options.
Dr. Farber is a medical instructor at Duke University Health System in Durham, N.C. Dr. Stafford is a medical instructor at Duke University. Dr. Sata is assistant professor of medicine at Duke University. Dr. Abdo and Dr. Menon are hospitalists at Duke University. Dr. Brooks is assistant professor of medicine at Duke University. Dr. Wachter is associate medical director at Duke Regional Hospital and assistant professor of medicine at Duke University. Dr. Sharma is associate medical director for clinical education in hospital medicine at Duke Regional Hospital and assistant professor of medicine at Duke University.
References
1. January CT et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;139. doi: 1161/CIR.0000000000000665.
2. Lippi G et al. Direct oral anticoagulants: Analysis of worldwide use and popularity using Google Trends. Ann Transl Med. 2017 Aug; 5(16):322. doi: 10.21037/atm.2017.06.65.
3. Turakhia MP et al. Chronic kidney disease and arrhythmias: Conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Eur Heart J. 2018 Jun 21;39(24):2314-25. doi: 10.1093/eurheartj/ehy060.
4. Siontis KC et al. Outcomes associated with apixaban use in patients with end-stage kidney disease and atrial fibrillation in the United States. Circulation. 2018 Oct 9;138(15):1519-29. doi: 10.1161/CIRCULATIONAHA.118.035418.
5. Nigwekar SU et al. Long-term anticoagulation for patient receiving dialysis: Tilting the benefit-to-risk ratio? Circulation. 2018 Oct 9;138(15):1530-3. doi: 10.1161/CIRCULATIONAHA.118.037091.
Key points
- According to 2019 American Heart Association guidelines, warfarin or apixaban are reasonable options for stroke prevention for patients who have end-stage renal disease and who plan for anticoagulation because of atrial fibrillation.
- Recent observational data suggests that apixaban may be safer than warfarin in this population.
- Several randomized, controlled trials are ongoing that may help determine the optimal agent to use in this setting.
- Until more definitive data is available, a reasonable approach is to discuss the risks and benefits of various treatment strategies with patients, and engage a multidisciplinary team (cardiologist, nephrologist, primary care provider, pharmacist) in the decision making process.
Additional reading
January CT et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019;139. doi: 1161/CIR.0000000000000665.
Nigwekar SU et al. Long-term anticoagulation for patient receiving dialysis: Tilting the benefit to risk ratio? Circulation. 2018 Oct 9;138(15):1530-3. doi: 10.1161/CIRCULATIONAHA.118.037091.
Garlo KG et al. Demystifying the benefits and harms of anticoagulation for atrial fibrillation in chronic kidney disease. Clin J Am Soc Nephrol 2019;14:125-36. doi: 10.2215/CJN.06430518.
Quiz
Two days ago you admitted a 72-year-old woman with end-stage renal disease on dialysis who had developed new-onset atrial fibrillation causing a mild acute diastolic congestive heart failure exacerbation. Transthoracic ECG showed a preserved left ventricular ejection fraction and no significant valvular disease. After two sessions of dialysis in the hospital and initiation of a beta-blocker for control of her heart rate, she is stable and ready for discharge. Her discharge weight is 75 kg.
Which of the following recommendations should you make to this patient regarding anticoagulation for prevention of stroke and systemic embolism from atrial fibrillation?
A. Take warfarin with a international normalized ratio goal of 2.5.
B. Take apixaban 2.5 mg twice a day.
C. Take apixaban 5 mg twice a day.
D. Discuss the risks/benefits of various treatment approaches with the patient, and involve the hospital pharmacist as well as the patient’s nephrologist, cardiologist, and/or primary care provider in the decision making process to reach a consensus and to ensure a safe follow-up plan.
The best answer is D. While A, B, and C are all reasonable approaches based on the available data and current guidelines, the best approach is to involve the patient and the multidisciplinary team in the decision making process. When more clinical trial data becomes available in the future, the optimal approach to managing patients such as this one may become clearer, but until then it makes sense to take into account individual patient characteristics and patient preferences.