Left Atrial Appendage Occlusion Study II

A pilot, multicentre randomized controlled study of surgical left atrial occlusion (LAA) in 50 patients with atrial fibrillation/flutter undergoing cardiac surgery requiring cardiopulmonary bypass with additional risk factors for late stroke. Patients will be enrolled and randomized to undergo LAA exclusion and aspirin therapy or best medical therapy as per guidelines. Main research questions: 1. Can successful occlusion of the LAA be safely achieved by cut and sew or stapler techniques? 2. In patients with atrial fibrillation with 2 or more risk factors for stroke, will removal of the left atrial appendage (LAA) and aspirin therapy reduce the risk of systemic embolic events and major bleeding compared to warfarin?