Left Atrial Appendage Closure Meta-Analysis | Journal Scan

Study Questions:

What are the outcomes associated with left atrial appendage closure (LAAC) as compared to warfarin for stroke prevention in atrial fibrillation?


Using patient-level data from two randomized trials (PROTECT AF and PREVAIL) and two registries (CAP and CAP2), 2,406 patients with atrial fibrillation were evaluated after implantation of the Watchman LAAC device or warfarin. Mean follow-up was 2.69 years. Reported analyses were primarily performed on the two randomized trials. The primary outcome was a composite of stroke, systemic embolism, and cardiovascular death. Secondary outcomes included individual components of the composite, as well as hemorrhagic stroke, cardiovascular/unexplained death, nonprocedural bleeding, and ischemic stroke.


There was no difference in the rate of the primary outcome between the LAAC and warfarin groups (2.72 vs. 3.50 events/100 patient-years, hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.53-1.2). Use of an LAAC as compared to warfarin was associated with fewer hemorrhagic strokes (0.15 vs. 0.96 events/100 patient-years, HR, 0.22; 95% CI, 0.08-0.61) and less cardiovascular/unexplained death (1.1 vs. 2.3 events/100 patient-years, HR, 0.48; 95% CI, 0.28-0.61) and less nonprocedural bleeding (6.0% vs. 11.3%, HR, 0.51; 95% CI, 0.33-0.77). Rates of all-cause stroke or systemic embolism were similar between the two groups (1.75 vs. 1.87 events/100 patient-years, HR, 1.02; 95% CI, 0.62-1.7). Rates of ischemic stroke were higher in the LAAC group as compared to warfarin (1.6 vs. 0.9 events/100 patient-years, HR, 1.95; p = 0.05) driven by higher rates of procedure-related strokes in the LAAC group.


The authors concluded that the LAAC device resulted in improved rates of hemorrhagic stroke, cardiovascular death, and nonprocedural bleeding as compared to warfarin for stroke prevention in AF patients.


This study attempts to summarize data from the two randomized trials of LAAC versus warfarin in atrial fibrillation patients using a patient-level meta-analysis. There were distinct differences between the two trials including differences in training physicians to place the Watchman device and patient selection. Nonetheless, this study does highlight the range of potential outcomes that might be seen in real-world practice. It is important for clinicians to note that while hemorrhagic stroke rates were lower in the LAAC device group, the rate of hemorrhagic stroke in warfarin-treated patients was significantly higher than in other recent atrial fibrillation studies. Additionally, there was no difference in the primary composite outcome and an increase in ischemic stroke as compared to warfarin-treated patients. While LAAC is not a replacement for ALL patients with atrial fibrillation, it appears to be a viable option for some patients in whom anticoagulation is particularly high risk.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Appendage, Atrial Fibrillation, Embolism, Follow-Up Studies, Hemorrhage, Intracranial Hemorrhages, Patient Selection, Primary Prevention, Registries, Stroke, Warfarin

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