LAAO using speci c percutaneous devices (WATCHMAN, Amplatzer Cardiac Plug, or WaveCrest device or the Lariat endocardial and epicardial ligation technique) or occlusion during a cardiac surgery procedure with either LAA amputation and closure or a stapler device have been proposed and tested for patients with AF at high risk of stroke in the presence of a high risk of bleeding or in the presence of contraindications to OACs. Two randomized studies evaluated the WATCHMAN (Atritech, Inc) device vs warfarin: the Watchman Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation (PROTECT AF) and the Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy (PREVAIL AF).446-452 In the PROTECT AF trial, the ef cacy of LAA closure with the device met the pre-speci ed criteria for non-inferiority vs warfarin, but the rate of adverse safety events in the intervention group was 4.4% with evidence of harmful periprocedural complications (pericardial effusion and procedure-related ischemic stroke). 