Clinical Risk Factors of Thromboembolic and Major Bleeding Events for Patients with Atrial Fibrillation Treated with Rivaroxaban in Japan.

ABSTRACT

BACKGROUND: It is important to understand the risk of thromboembolism and bleeding in patients with nonvalvular atrial fibrillation (NVAF) receiving direct oral anticoagulants; however, data on risk factors in Japanese patients are limited. METHODS: XAPASS (Xarelto Post-Authorization Safety and Effectiveness Study in Japanese Patients with Atrial Fibrillation) is a prospective observational study examining the safety and effectiveness of rivaroxaban in Japanese real-world clinical practice. We investigated risk factors for stroke/noncentral nervous system systemic embolism (non-CNS SE)/myocardial infarction (MI) and major bleeding using 1-year follow-up data. Associations between baseline characteristics and outcomes were examined by Cox regression analysis. RESULTS: During April 2012-June 2014, 11,308 patients newly started with rivaroxaban treatment were enrolled. Of 9578 patients with 1-year data fixed as of September 2017, 6220 patients who received appropriate dosages of rivaroxaban for their creatinine clearance were included in the present safety outcomes subanalysis, and 6198 were included in the effectiveness outcomes analysis. Stroke/non-CNS SE/MI was observed in 97 of 6198 patients (1.6%, 1.8 events/100 patient-years), and major bleeding occurred in 102 of 6220 patients (1.6%, 1.9 events/100 patient-years). Age greater than or equal to 75 years (hazard ratio [HR] 2.27; [95% confidence interval (CI) 1.49, 3.47]), prior ischemic stroke/transient ischemic attack (2.08; [1.38, 3.13]), and antiplatelet use (3.23; [1.83, 5.70]) were associated with stroke/non-CNS SE/MI. Creatinine clearance less than 50 mL/min (HR 1.86; [95% CI 1.26, 2.75]), diabetes (1.55; [1.02, 2.35]), and antiplatelet use (3.04; [1.70, 5.45]) were associated with major bleeding. CONCLUSIONS: These results would help physicians to assess risks in Japanese patients with NVAF receiving rivaroxaban.