Rivaroxaban in Patients with Atrial Fibrillation and a Bioprosthetic Mitral Valve

The study aimed to assess the effects of rivaroxaban in patients with atrial fibrillation and a bioprosthetic mitral valve, where previous data were uncertain. This randomized trial compared rivaroxaban (20 mg once daily) with dose-adjusted warfarin (target international normalized ratio, 2.0 to 3.0). The primary outcome was a composite of death, major cardiovascular events (stroke, transient ischemic attack, systemic embolism, valve thrombosis, or hospitalization for heart failure), or major bleeding at 12 months.

A total of 1005 patients were enrolled across 49 sites in Brazil. A primary-outcome event occurred at a mean of 347.5 days in the rivaroxaban group and 340.1 days in the warfarin group, demonstrating noninferiority for rivaroxaban (difference calculated as restricted mean survival time, 7.4 days; 95% CI, -1.4 to 16.3; P<0.001). Death from cardiovascular causes or thromboembolic events occurred in 3.4% of the rivaroxaban group versus 5.1% in the warfarin group (hazard ratio, 0.65; 95% CI, 0.35 to 1.20). The incidence of stroke was notably lower in the rivaroxaban group (0.6%) compared to the warfarin group (2.4%) (hazard ratio, 0.25; 95% CI, 0.07 to 0.88). Major bleeding occurred in 1.4% of the rivaroxaban group and 2.6% of the warfarin group (hazard ratio, 0.54; 95% CI, 0.21 to 1.35). Other serious adverse events were similar between the groups.

In conclusion, for patients with atrial fibrillation and a bioprosthetic mitral valve, rivaroxaban was found to be noninferior to warfarin regarding the mean time until the primary outcome of death, major cardiovascular events, or major bleeding at 12 months ^{See more See less}