Comparing Stroke and Bleeding with Rivaroxaban and Dabigatran in Atrial Fibrillation: Analysis of the US Medicare Part D Data.

Abstract

No studies have directly compared the effectiveness and safety of dabigatran and rivaroxaban using US Medicare data. Our objective was to compare effectiveness and safety between rivaroxaban 20mg/dabigatran 150mg and rivaroxaban 15mg/dabigatran 75mg among patients with atrial fibrillation (AF). Using 2010-2013 US Medicare Part D data, we selected patients with AF initiating dabigatran 150/75mg or rivaroxaban 20/15mg between 4 November 2011 (when rivaroxaban was approved) and 31 December 2013. Our sample included 7322 patients receiving dabigatran 150mg, 5799 patients receiving rivaroxaban 20mg, 1818 receiving dabigatran 75mg, and 2568 receiving rivaroxaban 15mg. We followed them until stroke, other thromboembolic events, bleeding, discontinuation or switch of an anticoagulant, death, or 31 December 2013. We constructed Cox proportional hazard models with propensity score weighting to compare clinical outcomes between groups. There was no difference in the risk of stroke between dabigatran 150mg and rivaroxaban 20mg (hazard ratio [HR] 1.05; 95% confidence interval [CI] 0.97-1.13) or between dabigatran 75mg and rivaroxaban 15mg (HR 1.05; 95% CI 0.94-1.18). Compared with dabigatran 150mg, rivaroxaban 20mg was associated with a higher risk of other thromboembolic events (HR 1.28; 95% CI 1.14-1.44), major bleeding (HR 1.32; 95% CI 1.17-1.50), and death (HR 1.36; 95% CI 1.19-1.56). The risk of thromboembolic events other than stroke (HR 1.37; 95% CI 1.15-1.62), major bleeding (HR 1.51; 95% CI 1.25-1.82), and death (HR 1.21; 95% CI 1.04-1.41) was also higher for rivaroxaban 15mg than for dabigatran 75mg. There was no difference in stroke prevention between rivaroxaban and dabigatran; however, rivaroxaban was associated with a higher risk of thromboembolic events other than stroke, death, and bleeding.