Characterizing the Safety Profile of Apixaban Versus Warfarin in Moderate to Severe Chronic Kidney Disease at a Veterans Affairs Hospital

Background: Warfarin has been the cornerstone of therapy for patients with stage 4 and 5 chronic kidney disease (CKD) requiring anticoagulation. These patients were omitted from landmark clinical trials involving apixaban. Apixaban’s safety profile is still largely unclear in this population. Objectives: To compare major bleeding, secondary bleeding outcomes, stroke, and thromboembolism in veterans with CKD stage 4, with CKD stage 5, and on dialysis on apixaban or warfarin. Methods: A retrospective chart review identified veterans with CKD stage 4 and stage 5, and on dialysis who received either apixaban or warfarin from 2013 to 2019 at the Memphis Veterans Affairs Medical Center. The primary outcome was incidence of major bleeding. Secondary outcomes were clinically relevant nonmajor and minor bleeding, composite bleeding, venous thromboembolism (VTE), and stroke. Results: A total of 111 patients were included in this study (warfarin group, n = 57; apixaban group, n = 54). Primary and secondary outcomes were analyzed using the χ² or Fisher exact tests as appropriate. There was no difference in major bleeding between groups (14% vs 7%, P = 0.362). There were increased rates of minor bleeding (26% vs 6%, P = 0.004) and composite bleeding (46% vs 20%, P = 0.004) in patients receiving warfarin. There were no differences in rates of stroke or VTE between the 2 groups. Conclusion and Relevance: There was no difference in major bleeding in patients who received apixaban compared with warfarin. Apixaban may be a reasonable alternative to warfarin in veterans with CKD stage 4 and 5, including those on dialysis.