Rivaroxaban versus warfarin in patients with nonvalvular atrial fibrillation and stage IV-V chronic kidney disease

BACKGROUND: There is limited evidence on the effectiveness and safety of direct-acting oral anticoagulants in patients with nonvalvular atrial fibrillation (NVAF) and advanced chronic kidney disease (CKD). This study compared the risks of ischemic stroke/systemic embolism (ISSE) and major bleeding in patients with NVAF and stage IV-V CKD treated with rivaroxaban or warfarin. METHODS: Patients with NVAF and stage IV-V CKD who initiated rivaroxaban or warfarin treatment between November 2011 and June 2018 were selected from the Optum® Deidentified Electronic Health Record Database. Propensity score matching was used to balance rivaroxaban and warfarin patients on 112 measured baseline covariates. ISSE and major bleeding events over 2 years following treatment initiation were ascertained with validated end point definitions. Outcomes were analyzed as time-to-event data using Kaplan-Meier survival estimators and Cox regression. RESULTS: A total of 781 eligible rivaroxaban-treated patients were propensity score-matched to 1,536 warfarin-treated patients; baseline covariates were well balanced after matching (absolute standardized differences <0.1). The average patient age was 80 years; 60.5% were female; 81.3% and 18.7% had CKD stage IV and V, respectively. Hazard ratios for rivaroxaban compared to warfarin were 0.93 (95% CI 0.46-1.90, P = .85) for the risk of ISSE and 0.91 (95% CI 0.65-1.28, P = .60) for major bleeding. CONCLUSIONS: No statistically significant difference in the risk of ISSE or major bleeding was found between rivaroxaban- and warfarin-treated patients. Although further study is needed, rivaroxaban appears to be a reasonable alternative to warfarin for ISSE prevention in the setting of NVAF and stage IV-V CKD.