Long-Term Anticoagulation for Patients Receiving Dialysis

Abstract

Article, see p 1519 I t has been >6 decades since the earliest demonstration of dialysis as a lifesaving therapy for patients with severely impaired kidney function. Globally, an estimated 2 million patients are receiving maintenance dialysis for end-stage renal disease, and between 1990 and 2010, a remarkable 70% growth in patients receiving maintenance dialysis was noted. 1 This unidirectional trend is likely to continue unabated. Unfortunately, mortality and morbidity remain high in patients on dialysis. Car-diovascular disease is the leading cause of death. There are many reasons for the relentless burden of cardiovascular events in the dialysis population. Biological differences between patients receiving dialysis and those not receiving dialysis may explain the failure to extend the benefits of therapies observed in patients not on dialysis to patients on dialysis. More important, patients on dialysis are often excluded from large cardiovascular-focused randomized controlled trials, which significantly limits the evidence needed to make clinical decisions. As a result, clini-cians caring for patients receiving dialysis frequently find themselves extrapolating information on safety and efficacy from nondialysis clinical trials. How confident can they be? As we await trial evidence, careful analyses of data from large observational cohorts can augment our understanding of outcomes, particularly of adverse events. In the current issue of Circulation, Siontis et al 2 examine the outcomes associated with the use of apixaban, an oral factor Xa inhibitor, in patients with nonval-vular atrial fibrillation who are receiving dialysis. Their observational study included >25 000 Medicare beneficiaries (mean age, 68.2 years; male, 54.3%; hemodialy-sis, 94.6%) from the US Renal Data System, a national data registry funded by the National Institute of Diabetes and Digestive and Kidney Diseases. Overall, 9.2% of patients were prescribed apixaban, and the remaining were treated with warfarin. The authors noted, however, a remarkable increase in the number of new apixa-ban prescriptions over the study period extending from October 2010 to Decem-ber 2015, with >1 in 4 new anticoagulation prescriptions in 2015 for apixaban. In a prognosis-based propensity score analysis, there was no difference between apixaban and warfarin in the risk of stroke or systemic embolism. The risk of major bleeding, however, was 28% lower with apixaban (95% CI, 13-41). In patients with normal kidney function who develop nonvalvular atrial fibril-lation, anticoagulation therapy to reduce systemic thromboembolism has been the standard of care based on rigorous data from randomized controlled trials. In a meta-analysis that included 6 trials (n=2900 patients) comparing warfarin with controls, warfarin treatment reduced ischemic stroke by 67% (95% CI, 54-77), all stroke (ischemic and hemorrhagic) by 64% (95% CI, 49-74), and all