Antithrombotic Therapy for Atrial Fibrillation with Stable Coronary Disease

Abstract

Background: There are limited data from randomized trials evaluating the use of antithrombotic therapy in patients with atrial fibrillation and stable coronary artery disease.

Methods: In a multicenter, open-label trial conducted in Japan, we randomly assigned 2236 patients with atrial fibrillation who had undergone percutaneous coronary intervention (PCI) or coronary-artery bypass grafting (CABG) more than 1 year earlier or who had angiographically confirmed coronary artery disease not requiring revascularization to receive monotherapy with rivaroxaban (a non-vitamin K antagonist oral anticoagulant) or combination therapy with rivaroxaban plus a single antiplatelet agent. The primary efficacy end point was a composite of stroke, systemic embolism, myocardial infarction, unstable angina requiring revascularization, or death from any cause; this end point was analyzed for noninferiority with a noninferiority margin of 1.46. The primary safety end point was major bleeding, according to the criteria of the International Society on Thrombosis and Hemostasis; this end point was analyzed for superiority.

Results: The trial was stopped early because of increased mortality in the combination-therapy group. Rivaroxaban monotherapy was noninferior to combination therapy for the primary efficacy end point, with event rates of 4.14% and 5.75% per patient-year, respectively (hazard ratio, 0.72; 95% confidence interval [CI], 0.55 to 0.95; P<0.001 for noninferiority). Rivaroxaban monotherapy was superior to combination therapy for the primary safety end point, with event rates of 1.62% and 2.76% per patient-year, respectively (hazard ratio, 0.59; 95% CI, 0.39 to 0.89; P = 0.01 for superiority).

Conclusions: As antithrombotic therapy, rivaroxaban monotherapy was noninferior to combination therapy for efficacy and superior for safety in patients with atrial fibrillation and stable coronary artery disease. (Funded by the Japan Cardiovascular Research Foundation; AFIRE UMIN Clinical Trials Registry number, UMIN000016612; and ClinicalTrials.gov number, NCT02642419.).