Residual stroke risk despite oral anticoagulation in patients with atrial fibrillation

Oral anticoagulation (OAC) reduces the risk of thromboembolic events in patients with atrial fibrillation (AF); however, thromboembolism (TE) still can occur despite OAC. Factors associated with residual risk for stroke, systemic embolism, or transient ischemic attack events despite OAC have not been well described.The purpose of this study was to evaluate the residual risk of thromboembolic events in patients with AF despite OAC.A total of 18,955 patients were analyzed in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF I and II) using multivariable Cox proportional hazard modeling. Mean age was 72 ± 10.7, and 42% were women. There were 451 outcome events.The risk of TE despite OAC increased with CHAPatients with AF have a residual risk of TE with increasing CHA