[Left atrial appendage clusure in nonvalvular atrial fibrillation : Clinical evidence 2017].

Nonvalvular atrial fibrillation (AF) is the most common arrhythmia with a prevalence of 1-2% and affects approximately 15-20% of all octogenarians. Patients are at increased risk of thromboembolic stroke, with an overall risk of 5% per year. Thrombi form almost exclusively in the left atrial appendage (LAA), a blind sac-like heterogeneous structure trabeculated by pectinate muscles. In the past five decades, life-long oral anticoagulation (OAC) with vitamin K antagonists (VKA) has been the state-of-the art treatment to prevent stroke and systemic embolism from thrombi in AF. In the last decade, nonvitamin K dependent oral anticoagulants (NOAC) have been shown to be superior to VKA. Given the safety issues of indefinite OAC with either VKA or NOAC, it is plausible to consider left atrial appendage closure (LAAC) as an alternative strategy to prevent death, stroke or other systemic embolization, and bleeding. In recent years, LAAC has been compared to VKA in prospective randomized trials, yielding superior results regarding efficacy and noninferiority regarding safety in the mid-term. This review provides an update on the current state of LAAC in the field of prevention of death, stroke, and bleedings in patients suffering from nonvalvular AF. We elucidate the evidence and limitations of anticoagulation as the classical treatment paradigm, and review devices and techniques for LAAC. Most importantly, the current clinical evidence on efficacy and safety is outlined.