Major bleeding increases the risk of subsequent cardiovascular events in patients with atrial fibrillation: insights from the SAKURA AF registry and RAFFINE registry

Background: Bleeding events are one of the major concerns in patients using oral anticoagulants (OACs). We aimed to evaluate the association between major bleeding and long-term clinical outcomes in atrial fibrillation (AF) patients taking OACs. Methods: We analyzed a database comprising two large-scale prospective registries of patients with documented AF: the RAFFINE and SAKURA registries. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE), defined as the composite of all-cause death, ischemic stroke, and myocardial infarction. Major bleeding was defined in accordance with the criteria of the International Society on Thrombosis and Hemostasis. Cox multivariate analysis was used to determine the impact of major bleeding on the incidence of MACCE. Results: The median follow-up period was 39.7 (interquartile range, 33.1–48.1) months. Among 6,633 patients with AF who were taking OAC, 298 (4.5%) had major bleeding and 737 (11.1%) had MACCE. The incidence of MACCE was higher in patients with bleeding than in those without (18.33 and 3.22, respectively, per 100 patient-years; log-rank p < 0.0001). Multivariate logistic regression analysis revealed older age, vitamin K antagonist use, and antiplatelet drug use as independent predictors of major bleeding. Median duration of MACCE occurrence after major bleeding was 41 (interquartile range, 3–300) days. Multivariate Cox hazard regression analysis showed that the risk of MACCE was significantly higher in patients with major bleeding compared to those without (hazard risk, 4.64; 95% confidence interval, 3.62–5.94; p < 0.0001). Conclusions: Major bleeding was associated with long-term adverse cardiovascular events among AF patients taking OAC. Therefore, reducing the risk of bleeding is important for improving clinical outcomes in patients with AF.