Left atrial appendage closure: a percutaneous transcatheter approach for stroke prevention in atrial fibrillation.

Atrial fibrillation is a frequent cause of stroke; in the elderly, more than 20% of strokes are attributed to this common arrhythmia. Anticoagulation with warfarin reduces the risk of stroke by ∼60%; however, a large proportion of patients with atrial fibrillation do not receive this treatment because of relative/absolute contraindications. Moreover, patients often discontinue warfarin for a variety of reasons and chronic warfarin administration rates remain suboptimal. Although the compliance with anticoagulation may improve with novel anticoagulants and bleeding risk can be somewhat reduced when compared with warfarin, there is still a progressive increase in bleeding complications over time. Accordingly, new approaches for stroke prevention in these patients are being explored and tested. In transoesophageal echocardiographic (TEE) studies, more than 90% of thrombi were found in the left atrial appendage (LAA) in non-valvular atrial fibrillation, and transcatheter LAA closure is developed and examined as a novel approach to reduce the risk of stroke in these patients. The PROTECT-AF study provides first evidence from a randomized clinical trial that a strategy of LAA occlusion using the Watchman device can be non-inferior to anticoagulation with warfarin for a combined endpoint in patients with non-valvular atrial fibrillation (mean CHADS(2) score 1.8). In successfully occluded patients fulfilling TEE criteria (86%), warfarin was stopped after 45 days, followed by aspirin and clopidogrel for 6 months after randomization and subsequently aspirin. The PREVAIL trial is further evaluating this concept. Limited data are available for another LAA occlusion system, the Amplatzer Cardiac Plug (ACP) device, for which the ACP trial has been initiated. Left atrial appendage occlusion needs to be performed with meticulous care by experienced operators because periprocedural complications such as pericardial effusion or stroke have been documented. With increased operator experience and technical improvements of the device, these complications can be minimized.