Introduction: Comorbid peripheral artery disease (PAD) is a risk factor for ischemic stroke in patients with nonvalular atrial fibrillation (NVAF) and has been incorporated into the CHA2DS2-VASc risk score.
Objective: To assess the effectiveness and safety of rivaroxaban vs. warfarin in NVAF patients with PAD treated in routine practice.
Methods: Using US MarketScan claims data from 11/2011-3/2016, we identified oral anticoagulation (OAC) naïve NVAF patients with PAD and ≥12 months of continuous insurance coverage prior to the qualifying OAC dispensing. Propensity scores were derived based on demographics, comorbidities, stroke and bleeding risk factors and concomitant medications and used to 1:1 match rivaroxaban to warfarin users. Balance between cohorts was evaluated by inspecting standardized differences for baseline covariates (differences >0.1 indicating imbalance). Patients were followed until an event, OAC discontinuation or switch (30 day permissible gap), insurance disenrollment or end of follow up. Rates of stroke/systemic embolism (SSE), ischemic stroke and intracranial hemorrhage (ICH) per 100 person years (PYs) were compared using Cox regression.
Results: We included 1030 rivaroxaban (35% received a reduced dose) and 1030 warfarin users with NVAF and PAD with a median (25%, 75% range) available follow up of 1.5 (0.7, 2.5) years. All baseline covariates had a standardized differences <0.1. Median age was 76 (69, 83) years and median CHA2DS2-VASc and HAS-BLED scores were 4 (3,4) and 2 (2,3). Rivaroxaban was associated with a 70% relative hazard reduction in SSE (absolute rate reduction [ARR]=1.48 events/100 PY; number needed to treat [NNT]=68) and a 75% reduction in ischemic stroke (ARR=1.42 events/100 PY; NNT=71) vs. warfarin (Figure). Only 1 ICH (in the rivaroxaban cohort) was observed.
Conclusions: In this real-world study, rivaroxaban was associated with reductions in SSE and ischemic stroke alone in NVAF patients with comorbid PAD.