Two-year outcomes of anticoagulation for acute ischemic stroke with nonvalvular atrial fibrillation ― SAMURAI-NVAF study

Background: We determined the 2-year long-term risk-benefit profile in patients with stroke or transient ischemic attack (TIA) receiving warfarin or direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF) using a prospective, multicenter, observational registry in Japan. Methods and Results: NVAF patients within 7 days after onset of ischemic stroke/TIA were enrolled in 18 stroke centers. Outcome measures included ischemic and bleeding events and death in the 2-year follow-up period. We enrolled 1,116 patients taking either warfarin (650 patients) or DOACs (466 patients) at acute hospital discharge. DOAC users were younger and had lower National Institutes of Health Stroke Scale, CHADS2 and discharge modified Rankin Scale scores than warfarin users (P<0.0001 each). Incidences of stroke/systemic embolism (adjusted hazard ratio, 1.07; 95% CI, 0.66–1.72), all ischemic events (1.13; 0.72–1.75), and ischemic stroke/TIA (1.58; 0.95–2.62) were similar between groups. Risks of intracranial hemorrhage (0.32; 0.09–0.97) and death (0.41; 0.26–0.63) were significantly lower for DOAC users. Infection was the leading cause of death, accounting for 40% of deaths among warfarin users. Conclusions: Stroke/TIA patients receiving DOACs for secondary prevention were younger and had lower stroke severity and risk indices than those receiving warfarin. Estimated cumulative incidences of stroke and systemic embolism within 2 years were similar between warfarin and DOACs users, but those of death and intracranial hemorrhage were significantly lower among DOAC users.