Rivaroxaban-once Daily, Oral, Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation: Rationale and Design of the ROCKET AF Study

Background: Atrial fibrillation (AF), the most common significant cardiac arrhythmia, increases the risk of stroke, particularly in the elderly. Warfarin is effective in reducing stroke risk but is burdensome to patients and is difficult to control. Rivaroxaban is an oral direct factor Xa inhibitor in advanced development as an alternative to warfarin for the prevention and treatment of thromboembolic disorders.

Methods: ROCKET AF is a randomized, double-blind, double-dummy, event-driven trial, which aims to establish the noninferiority of rivaroxaban compared with warfarin in patients with nonvalvular AF who have a history of stroke or at least 2 additional independent risk factors for future stroke. Patients are randomly assigned to receive rivaroxaban, 20 mg once daily (od), or dose-adjusted warfarin titrated to a target international normalized ratio (INR) of 2.5 (range 2.0-3.0, inclusive) using point-of-care INR devices to receive true or sham INR values, depending on the study drug allocation. The primary efficacy end point is a composite of all-cause stroke and noncentral nervous system systemic embolism. The primary safety end point is the composite of major and clinically relevant nonmajor bleeding events. Over 14,000 patients have been randomized at 1,100 sites across 45 countries, and will be followed until 405 primary outcome events are observed.

Conclusion: The ROCKET AF study will determine the efficacy and safety of rivaroxaban as an alternative to warfarin for the prevention of thromboembolism in patients with AF.