Rivaroxaban vsWarfarin Sodium in the Ultra-Early Period After Atrial Fibrillation-Related Mild Ischemic Stroke A Randomized Clinical Trial

Abstract

IMPORTANCE In atrial fibrillation (AF)-related acute ischemic stroke, the optimal oral anticoagulation strategy remains unclear. OBJECTIVE To test whether rivaroxaban or warfarin sodium is safer and more effective for preventing early recurrent stroke in patients with AF-related acute ischemic stroke. DESIGN, SETTING, AND PARTICIPANTS A randomized, multicenter, open-label, blinded end point evaluation, comparative phase 2 trial was conducted from April 28, 2014, to December 7, 2015, at 14 academic medical centers in South Korea among patients with mild AF-related stroke within the previous 5 days who were deemed suitable for early anticoagulation. Analysis was performed on a modified intent-to-treat basis. INTERVENTIONS Participants were randomized 1: 1 to receive rivaroxaban, 10mg/d for 5 days followed by 15 or 20mg/d, or warfarin with a target international normalized ratio of 2.0-3.0, for 4 weeks. MAIN OUTCOMES AND MEASURES The primary end pointwas the composite of new ischemic lesion or new intracranial hemorrhage seen on results of magnetic resonance imaging at 4 weeks. Primary analysis was performed in patients who received at least 1 dose of study medications and completed follow-up magnetic resonance imaging. Key secondary end points were individual components of the primary end point and hospitalization length. RESULTS Of 195 patients randomized, 183 individuals (76 women and 107 men; mean [SD] age, 70.4 [10.4] years) completed magnetic resonance imaging follow-up and were included in the primary end point analysis. The rivaroxaban group (n = 95) and warfarin group (n = 88) showed no differences in the primary end point (47 [49.5%] vs 48 [54.5%]; relative risk, 0.91; 95% CI, 0.69-1.20; P = .49) or its individual components (new ischemic lesion: 28 [29.5%] vs 31 of 87 [35.6%]; relative risk, 0.83; 95% CI, 0.54-1.26; P = .38; new intracranial hemorrhage: 30 [31.6%] vs 25 of 87 [28.7%]; relative risk, 1.10; 95% CI, 0.70-1.71; P = .68). Each group had 1 clinical ischemic stroke, and all new intracranial hemorrhages were asymptomatic hemorrhagic transformations. Hospitalization length was reduced with rivaroxaban compared with warfarin (median, 4.0 days [interquartile range, 2.0-6.0 days] vs 6.0 days [interquartile range, 4.0-8.0]; P < .001). CONCLUSIONS AND RELEVANCE In mild AF-related acute ischemic stroke, rivaroxaban and warfarin had comparable safety and efficacy.