Incidence of stroke, systemic embolism and bleeding events in patients without anticoagulation based on real-world data in Japan: a retrospective cohort study.

Approximately one-third of the patients do not receive any anticoagulation in the modern DOAC era in Japan. The SSE rate increases by the CHADS2 score. The SSE rate is low in patients with a CHADS2 score <1, supporting no indication of anticoagulation in current guidelines. In patients with a CHADS2 score >1, the use of anticoagulant drug therapy is recommended because of a higher risk of stroke.