Rivaroxaban Versus Warfarin in Patients With Nonvalvular Atrial Fibrillation and Severe Kidney Disease or Undergoing Hemodialysis

Abstract

Background: Patients with nonvalvular atrial fibrillation with stage 4 or 5 chronic kidney disease or undergoing hemodialysis were excluded from phase III randomized trials of nonvitamin K antagonist oral anticoagulants (NOACs). We sought to evaluate the effectiveness and safety of rivaroxaban compared with warfarin in patients with nonvalvular atrial fibrillation and stage 4 or 5 chronic kidney disease or undergoing hemodialysis in routine practice.

Methods: Using MarketScan data from January 2012 to December 2017, we identified patients on oral anticoagulant (OAC) with naïve nonvalvular atrial fibrillation and stage 4 or 5 chronic kidney disease or undergoing hemodialysis and with ≥12 months of insurance coverage before OAC initiation. Differences in baseline covariates between the rivaroxaban and warfarin cohorts were adjusted using inverse probability-of-treatment weights based on propensity scores calculated using generalized boosted models and 10,000 regression trees (absolute standardized differences <0.1 achieved for all covariates after adjustment). Patients were followed until a stroke/systemic embolism or major bleeding event, OAC discontinuation/switch, insurance disenrollment, or end of data availability. Hazard ratios (HRs) and 95% confidence intervals (CIs) comparing the OAC cohorts were calculated using Cox regression.

Results: We identified 1896 rivaroxaban (38.7% received a dose <20 mg/d) and 4848 warfarin users. Eighty-eight percent of included patients had stage 5 chronic kidney disease or were undergoing hemodialysis. Rivaroxaban did not significantly reduce stroke or systemic embolism (HR = 0.55, 95% CI = 0.27-1.10) or ischemic stroke (HR = 0.67, 95% CI = 0.30-1.50) alone, but it was associated with a significant 32% (95% CI = 1-53%) reduction in major bleeding risk compared with warfarin.

Conclusion: Among patients with nonvalvular atrial fibrillation and stage 4 or 5 chronic kidney disease or undergoing hemodialysis, rivaroxaban appears associated with significantly less major bleeding compared to warfarin.

Keywords: Atrial fibrillation; End-stage kidney disease; Hemodialysis; Oral anticoagulation; Rivaroxaban; Warfarin.