Systemic Embolism and Clinically Significant Bleeding Events in Older Adults with Nonvalvular Atrial Fibrillation After Treatment with Direct Oral Anticoagulants and Warfarin: A Retrospective Cohort Study in Japan.

Anticoagulant therapy, particularly the use of direct oral anticoagulant agents (DOACs), is recommended for patients with nonvalvular atrial fibrillation (NVAF). This multicenter observational retrospective cohort study aimed to assess the efficacy and safety of DOACs compared to warfarin in Japanese patients aged 75 years and older with NVAF. Data from the Mie-Life Innovation Promotion Center Database were used to collect medical information on the patients. The cumulative incidences of clinically significant bleeding events and systemic embolic events (SEEs) were analyzed. This study included 1787 older adult patients, of whom 1321 received DOACs (edoxaban: 428; apixaban: 586; dabigatran: 105; rivaroxaban: 202) and 466 receiving warfarin. There were no statistically significant differences in the cumulative incidence of bleeding events between the DOAC- and warfarin-treated groups. However, a statistically significant difference was observed for SEEs, with dabigatran showing a significantly lower incidence compared to warfarin. The incidence rates of bleeding events for individual DOACs were comparable to those for warfarin. Additionally, a history of vascular disorders was identified as a risk factor for bleeding events in the DOAC-treated group (hazard ratio (HR): 1.83, 95% confidence interval (CI): 1.16-2.88, < 0.01) and warfarin-treated group (HR: 1.80, 95% CI: 1.15-2.84, < 0.01). Based on real-world data, the overall efficacy and safety of DOACs were generally comparable to warfarin.