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Background: Nonvalvular atrial fibrillation (NVAF) patients experiencing prior stroke or systemic embolism (SSE) are at an increased risk of recurrent events. Limited real-world data exists comparing rivaroxaban or apixaban to warfarin in such patients. We sought to compare the effectiveness and safety of apixaban and rivaroxaban for secondary prevention of SSE in NVAF patients.
Methods: We performed a retrospective study using MarketScan claims from 1/2012-6/2015. Adults with ≥2 diagnosis codes for NVAF, a history of prior SSE, CHA2DS2-VASc score≥2 and ≥180 days of continuous medical and prescription benefits were included if they were newly initiated on rivaroxaban, apixaban or warfarin. Rivaroxaban or apixaban users were 1:1 propensity score matched individually to warfarin users. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for rivaroxaban and apixaban versus warfarin for ischemic stroke, intracranial hemorrhage (ICH) and major bleeding.
Results: Upon matching 2,342 rivaroxaban to 2,342 warfarin users, rivaroxaban was associated with a reduction in the composite endpoint of ischemic stroke or ICH versus warfarin (HR=0.52, 95%CI=0.32-0.83). Ischemic stroke was significantly (HR=0.57, 95%CI=0.33-0.97) and ICH nonsignificantly reduced (HR=0.43, 95%CI=0.16-1.18) by rivaroxaban. No significant difference in major bleeding was observed between rivaroxaban and warfarin (HR=1.29, 95%CI=0.81-2.05). After matching 1,217 apixaban and 1,217 warfarin users, apixaban was found to nonsignificantly reduce the combined endpoint of ischemic stroke or ICH versus warfarin (HR=0.69, 95%CI=0.32-1.48) and have a similar hazard of ischemic stroke (HR=1.10, 95%CI=0.47-2.53). Apixaban reduced ICH risk vs. warfarin (0 versus 6 events), but appeared to be associated with a similar risk of major bleeding (HR=0.95, 95%CI=0.44-2.06).
Conclusions: Among NVAF patients with a prior history of SSE, rivaroxaban reduced ischemic stroke and ICH risk versus warfarin and did not significantly impact major bleeding. Apixaban did not significantly alter patients’ risk of SSE or major bleeding compared to warfarin in this high-risk population.
Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Atrial Fibrillation and VT: Specific Situations and Newer Outcome Measures
Abstract Category: 8. Arrhythmias and Clinical EP: Supraventricular/Ventricular Arrhythmias
Presentation Number: 1190-106
- 2017 American College of Cardiology Foundation