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

Abstract

BackgroundPatients 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. MethodsUsing 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. ResultsWe 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. ConclusionAmong 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.