Three-Year Clinical Outcomes Associated With Warfarin vs. Direct Oral Anticoagulant Use Among Japanese Patients With Atrial Fibrillation　― Findings From the SAKURA AF Registry

Background: Although direct oral anticoagulants (DOACs) are widely used in Japanese patients with atrial fibrillation (AF), large-scale investigations into their use, with suitable follow-up times and rates, are lacking. Methods and Results: The SAKURA AF Registry is a prospective multicenter registry created to investigate therapeutic outcomes of oral anticoagulant (OAC) use in Japanese AF patients. We conducted a study involving 3,237 enrollees from 63 institutions in the Tokyo area being treated with any of 4 DOACs (n=1,676) or warfarin (n=1,561) and followed-up for a median of 39.3 months (range 28.5–43.6 months). Analyses of 1- and 2-year follow-up data available for 3,157 (97.5%) and 2,952 (91.2%) patients, respectively, showed no significant differences in rates of stroke or systemic embolism (SE), major bleeding, and all-cause mortality for DOAC vs. warfarin users (1.2 vs. 1.8%/year, 0.5 vs. 1.2%/year, and 2.1 vs. 1.7%/year, respectively). Under propensity score matching, the incidence of stroke or SE (P=0.679) and all-cause death (P=0.864) remained equivalent, but the incidence of major bleeding was significantly lower (P=0.014) among DOAC than warfarin users. Conclusions: A high follow-up rate allowed us to obtain reliable data on the status of OAC use and therapeutic outcomes among AF patients in Japan. Warfarin and DOACs appear to yield equivalent 3-year stroke and all-cause mortality rates, but DOACs appear to reduce the risk of major bleeding.