Treatment with the direct-acting oral anticoagulant apixaban in people with subclinical atrial fibrillation and a history of stroke or transient ischaemic attack led to a 7% absolute risk reduction in stroke or systemic embolism over 3·5 years, compared with a 1% absolute risk reduction for individuals without a previous history of stroke or transient ischaemic attack. The corresponding absolute increase in major bleeding was 3% and 1%, respectively. Apixaban could be considered for secondary stroke prevention in people with subclinical atrial fibrillation and a history of stroke or transient ischaemic attack.