Thromboembolic, Bleeding, and Mortality Risks of Rivaroxaban and Dabigatran in Asians With Nonvalvular Atrial Fibrillation

Abstract

Background: It is unclear whether the non-vitamin K antagonist oral anticoagulant agents rivaroxaban and dabigatran are superior to warfarin for efficacy and safety outcomes in Asians with nonvalvular atrial fibrillation (NVAF).

Objectives: The aim of this study was to compare the risk for thromboembolic events, bleeding, and mortality associated with rivaroxaban and dabigatran versus warfarin in Asians with NVAF.

Methods: A nationwide retrospective cohort study was conducted of consecutive patients with NVAF taking rivaroxaban (n = 3,916), dabigatran (n = 5,921), or warfarin (n = 5,251) using data collected from the Taiwan National Health Insurance Research Database between February 1, 2013 and December 31, 2013. The propensity score weighting method was used to balance covariates across study groups. Patients were followed until the first occurrence of any study outcome or the study end date (December 31, 2013).

Results: A total of 3,425 (87%) and 5,301 (90%) patients were taking low-dose rivaroxaban (10 to 15 mg once daily) and dabigatran (110 mg twice daily), respectively. Compared with warfarin, both rivaroxaban and dabigatran significantly decreased the risk for ischemic stroke or systemic embolism (p = 0.0004 and p = 0.0006, respectively), intracranial hemorrhage (p = 0.0007 and p = 0.0005, respectively), and all-cause mortality (p < 0.0001 and p < 0.0001, respectively) during the short follow-up period. In comparing the 2 non-vitamin K antagonist oral anticoagulant agents with each other, no differences were found regarding risk for ischemic stroke or systemic embolism, intracranial hemorrhage, myocardial infarction, or mortality. Rivaroxaban carried a significantly higher risk for hospitalization for gastrointestinal bleeding than dabigatran (p = 0.0416), but on-treatment analysis showed that the risk for hospitalized gastrointestinal bleeding was similar between the 2 drugs (p = 0.5783).

Conclusions: In real-world practice among Asians with NVAF, both rivaroxaban and dabigatran were associated with reduced risk for ischemic stroke or systemic embolism, intracranial hemorrhage, and all-cause mortality without significantly increased risk for acute myocardial infarction or hospitalization for gastrointestinal bleeding compared with warfarin.

Keywords: direct thrombin inhibitor; factor Xa inhibitor; hemorrhage; mortality; warfarin.