A new head-to-head study compared dabigatran (Pradaxa) and rivaroxaban (Xarelto) for the treatment of non-valvular atrial fibrillation (AF), and it appears that dabigatran may be the winner. Dr. David Graham and his team at the FDA’s Center for Drug Evaluation and Research performed a retrospective, new-user cohort study of nearly 120,000 patients with AF, 65 years of age who started dabigatran (150 mg twice a day) or rivaroxaban (20 mg once daily) for stroke prevention. Rivaroxaban was associated with a nonsignificant reduction in thromboembolic stroke (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.65-1.01; P = 0.07; adjusted incidence rate differences [AIRD] = 1.8 fewer cases/1,000 person-years), but a statistically significant increase in intracranial hemorrhage (ICH) (HR, 1.65; 95% CI, 1.20-2.26; P = 0.002; AIRD = 2.3 excess cases/1,000 person-years) and major extracranial bleeding (HR, 1.48; 95% CI, 1.32-1.67; P < 0.001; AIRD = 13.0 excess cases/1,000 person-years), including major gastrointestinal bleeding (HR, 1.40; 95% CI, 1.23-1.59; P < 0.001; AIRD = 9.4 excess cases/1,000 person-years), and with a statistically nonsignificant increase in mortality (HR, 1.15; 95% CI, 1.00-1.32; P = 0.051; AIRD = 3.1 excess cases/1,000 person-years). Mortality was statistically higher for rivaroxaban-treated patients 75 years of age or with a CHADS2 score > 2. The authors concluded that rivaroxaban use for AF was associated with significantly higher rates of ICH and major extracranial bleeding, including major gastrointestinal bleeding and possibly increased mortality in the elderly or those with higher risk of stroke compared to dabigatran (JAMA Intern Med. Published online Oct. 3, 2016. doi:10.1001/jamainternmed.2016.5954). There was no mention of use of idarucizumab (Praxbind) as a reversal agent for dabigatran during the study period.