Background: Because thrombi typically form in the left atrial appendage, LAAC may be an alternative to chronic oral anticoagulation in nonvalvular atrial fibrillation. Two prior randomized controlled trials compared outcomes in patients treated with LAAC with outcomes with warfarin. PROTECT AF trial showed noninferiority of LAAC to warfarin but noted high procedural complication rates. Subsequently, PREVAIL trial failed to demonstrate noninferiority, although complication rates were low overall and similar in both groups. However, longer-term follow-up data were lacking.
Study design: Patient-level meta-analysis of two prospective randomized trials.
Setting: Fifty-nine centers in the United States and Europe (PROTECT AF trial) and 41 centers in the United States (PREVAIL trial).
Synopsis: Meta-analysis of 5-year follow-up data from 1,114 adult patients with atrial fibrillation, most with CHADS2 score greater than or equal to 2 , randomized to receive LAAC or warfarin showed similar frequency of the composite endpoint of stroke, systemic embolism, or cardiovascular/unexplained death (hazard ratio, 0.820; P = .27). Subgroup analysis showed no significant difference in outcomes by patient subset, including CHADS2 or HAS-BLED scores. While the rate of ischemic stroke was similar between groups, the rates of hemorrhagic and disabling/fatal stroke were significantly lower with LAAC (HR, 0.20; P = .0022 and HR, 0.45; P = .034, respectively). All-cause and cardiovascular mortality also were significantly lower with LAAC (HR, 0.73; P = .035 and HR, 0.59; P = .027, respectively), likely because of lower incidence of hemorrhagic stroke.
These data cannot be generalized to patients who have an absolute contraindication to anticoagulation, as these patients were excluded. Further, these trials were conducted before widespread clinical use of novel oral anticoagulants, and LAAC has not yet been compared with these anticoagulants.
Bottom line: In patients with nonvalvular atrial fibrillation, LAAC with the Watchman device provides all-stroke prevention comparable with that of warfarin, and is associated with significantly lower rates of hemorrhagic stroke, disabling or fatal stroke, and mortality.
Citation: Reddy VY et al. 5-year outcomes after left atrial appendage closure: From the PREVAIL and PROTECT AF trials. J Am Coll Cardiol. 2017;70(24):2964-75.
Dr. Indovina is a hospitalist at Denver Health Medical Center and an assistant professor of medicine at the University of Colorado at Denver, Aurora.