In patients with device-detected atrial fibrillation and a prior stroke, oral anticoagulation increases bleeding without a clear reduction in stroke. This finding was presented by Prof. Paulus Kirchhof, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany, in a late-breaking clinical trials session at the annual congress of the American Heart Rhythm Society (HRS 2024) held in Boston, U.S., May 16–19.