ABSTRACT: The nonvitamin K antagonist oral anticoagulants have recently become available as an alternative to warfarin as stroke prophylaxis in atrial fibrillation, but data on real-life patient experience, including bleeding risk, are lacking. Our objective was to compare major bleeding events and nonpersistence between the nonvitamin K antagonist oral anticoagulant apixaban and other nonvitamin K antagonist oral anticoagulants (dabigatran and rivaroxaban) and warfarin in a contemporary, nation-wide cohort of patients with nonvalvular atrial fibrillation.Of 54 321 patients (median age, 73 years; 56% male; mean CHA2DS2-VASc score, 2.9), 7963, 6715, 15 413, and 24 230 patients initiated apixaban, rivaroxaban, dabigatran, and warfarin, respectively. Apixaban and rivaroxaban initiators were older, less often male, with higher HAS-BLED and CHA2DS2-VASc scores compared with dabigatran and warfarin initiators. A total of 2418 patients (4.5%) experienced a major bleeding event over all available follow-up. In this period, rivaroxaban (hazard ratio [HR] [95% CI], 1.49 [1.27-1.77]), dabigatran (HR, 1.17 [1.00-1.38]), and warfarin (HR, 1.23 [1.05-1.43]) users were significantly more likely to bleed than apixaban users. Findings were similar when restricted to the first 30 days after OAC initiation. Risk of nonpersistence was higher for dabigatran (HR, 1.45 [1.33-1.59]) and warfarin initiators (HR, 1.22 [1.12-1.33]), but not for rivaroxaban initiators (HR, 1.07 [0.96-1.20]) compared with apixaban initiators.In a real-world cohort of nonvalvular atrial fibrillation patients, apixaban had a lower adjusted major bleeding risk compared with rivaroxaban, dabigatran, and warfarin. Apixaban had a lower risk of nonpersistence compared with dabigatran and warfarin and similar risk compared with rivaroxaban.
