Abstract 14877: Dabigatran versus Warfarin Among Patients with Atrial Fibrillation: Real-World Post-Market Results

Abstract

Introduction: The Randomized Evaluation of Long-term Anticoagulation Therapy (RE-LY) trial demonstrated dabigatran (150mg) to be superior to warfarin for stroke prevention in atrial fibrillation (AF) but reported an increased risk of gastrointestinal bleeding (GIB) and myocardial infarction (MI) among dabigatran users.

Hypothesis: Dabigatran may be associated with increased risk of MI and GIB, but post-market data regarding its safety and effectiveness as compared to warfarin are lacking.

Methods: Incident users of dabigatran (n=14297) or warfarin (n=33548) with AF were identified from claims data within the Military Healthcare System between Nov 2010-May 2012. Patients with continuous enrollment for 1 year prior to index exposure were identified and followed for 1 year for hospitalization for GIB, MI, ischemic stroke and intracranial hemorrhage (ICH). Cox proportional hazard models were used to estimate crude and adjusted outcome rates.

Results: Dabigatran users were younger (74 vs 76 years; p<.01) and had relatively fewer cardiovascular risk factors. Overall, there were 187, 115, 93, and 81 events for GIB, ischemic stroke, MI and ICH, respectively. Adjusted rate of GIB (adjusted hazards ratio [aHR] 1.66; 95% confidence interval [CI] 1.20-2.20) was higher for dabigatran versus warfarin users. Rates of MI (aHR 0.53; CI 0.31-0.88) and ICH (aHR 0.44; CI 0.24-0.79) were significantly lower for dabigatran versus warfarin users. There was no difference in stroke rates (aHR dabigatran 1.10; CI 0.71-1.60) between groups (Table).

Conclusions: Findings for GIB and ICH are consistent with results from the RE-LY trial. We observed no increased risk of MI associated with dabigatran as compared to warfarin use.