Current evidence and indications for left atrial appendage closure.

Atrial fibrillation (AF) is the most common arrhythmia worldwide and its prevalence increases with age. The main and most severe complication of AF is ischemic stroke, yet an estimated 50 % of eligible patients cannot tolerate or are contraindicated to receive oral anticoagulation (OAC). In patients with AF, the left atrial appendage (LAA) is the main source of thrombus formation. Percutaneous LAA closure (LAAC) has emerged over the past two decades as a valuable alternative to OAC for reducing the risk of strokes and systemic embolisms in patients with AF who cannot tolerate long-term OAC. With newer generation devices such as the Watchman (Boston Scientific, Natick, MA, USA) and Amulet (Abbott, Abbott Park, IL, USA) gaining approval from the US Food and Drug Administration in recent years, the safety and efficacy of LAAC in specific populations intolerant to OAC have increased and more patients are being treated. This systematic review provides the indications for LAAC and the evidence for evaluating the use of the currently available device therapies. We also examine the current unsolved problems with patient selection and postprocedural antithrombotic regimens.