P4813Effectiveness and safety of rivaroxaban versus warfarin in patients with nonvalvular atrial fibrillation and heart failure

Abstract

Background: Heart failure (HF) is a common comorbidity in nonvalular atrial fibrillation (NVAF) patients and a potent risk factor for stroke. There is a paucity of data comparing rivaroxaban to warfarin in NVAF patients with HF treated in routine practice. Purpose: To assess the real-world effectiveness and safety of rivaroxaban and warfarin in NVAF patients with HF. Methods: Using United States Truven MarketScan claims data from 11/2011- 12/2016, we identified oral anticoagulation (OAC)-naive NVAF patients with comorbid HF and ≥12-months of continuous medical and prescription insurance coverage prior to the qualifying OAC dispensing. Rivaroxaban users were 1:1 matched to warfarin users via propensity-scores calculated based on demographics, comorbidities, components of the CHA2DS2-VASc and HAS-BLED risk scores and concomitant non-OAC medications (with residual standardized differences <0.1 being achieved for all covariates after matching). Patients were followed until an event, OAC switch/discontinuation (30-day permissible gap), insurance disenrollment or end of follow-up. Rates of stroke/systemic embolism (SSE) and major bleeding (per the Cunningham algorithm) were compared using Cox regression and reported as hazard ratios (HRs) and 95% confidence intervals (CIs). Results: We assessed 3,418 rivaroxaban (32% receiving the reduced dose) and 3,418 warfarin users with NVAF and HF with a median (interquartile range) available follow-up of 1.4 (0.6, 2.5) years. Median patient age was 74 (63, 82) years and median CHA2DS2-VASc and HAS-BLED scores were 4 (3, 5) and 2 (2, 3). The relative hazard of developing SSE (HR=0.82), ischemic stroke (HR=0.77) and major bleeding (HR=0.98) were not found to be different between rivaroxaban and warfarin users (Figure). Conclusion: Rivaroxaban's effectiveness and safety versus warfarin appears maintained in NVAF patients with HF treated in routine practice. Our findings may provide additional reassurance to clinicians regarding the effectiveness and safety of rivaroxaban in NVAF patients with comorbid HF.