In people with atrial fibrillation, a history of stroke is associated with increased risk of future cerebrovascular events compared with individuals without a history of stroke. Furthermore, people with atrial fibrillation and a history of stroke are more likely to benefit from oral anticoagulation than are those without a history of stroke. However, the effect of a past cerebrovascular event on the effectiveness of anticoagulation in people with device-detected atrial fibrillation is unclear.