We currently lack significant data or clear cut guidelines for closing left atrial appendage in patients with LAA for prevention of stroke. The current ACC/AHA/HRS guidelines recommends anticoagulation in patients with atrial fibrillation and CHA2DS2-VASc >2 (Grade Ia) irrespective of presence or absence of LAA.
The PROTECT AF trial was a randomized non-inferior trial that studied the usefulness of WATCHMAN device in closing LAA and prevention of stroke. The trial did show non-inferiority of the device closure vs warfarin anticoagulation but it was associated with higher side effects which were mostly periprocedural.
Based on this trial, the 2012 Focus European Society of Cardiology Guidelines called for “LAA closure/occlusion/excision” using percutaneous device in patients who are at high stroke risk and have contraindications for long-term oral anticoagulation (Class IIb; Level of Evidence B). The current AHA/ACC/HRS, however, does not include recommendations of LAA closure devices due to lack of enough robust evidence. However, both ESC and AHA/ACC guidelines suggest that surgical excision of the LAA may be considered in patients undergoing cardiac surgery or thoracoscopic atrial fibrillation surgery (Grade IIB)
Sources: Lancet, 2015 ACC/HRS/SCAI LAA Occlusion Device Societal Overview