WATCHMAN and Amplatzer Amulet for left atrial appendage occlusion: a systematic review and meta-analysis
Background: WATCHMAN and Amplatzer Amulet devices are an effective alternative to oral anticoagulation for left atrial appendage closure (LAAC) in non-valvular atrial fibrillation (NVAF) patients. This study aims to compare their safety and efficacy. Methods: This systematic review and meta-analysis followed PRISMA guidelines. PubMed, Embase, and ScienceDirect, were searched from inception to May 2025 for comparative studies in NVAF patients. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using random-effects models. Heterogeneity was assessed via I2 statistic; statistical significance was at P < 0.05. Results: Sixteen studies were included. No significant differences were found in ischemic stroke (RR 1.10, 95% CI 0.83–1.46; P = 0.51; I2 = 0%), all-cause mortality (RR 0.92, 95% CI 0.75–1.14; P = 0.45; I2 = 0%), major bleeding (RR 1.11, 95% CI 0.90–1.38; P = 0.33; I2 = 0%), minor bleeding (RR 1.11, 95% CI 0.76–1.61; P = 0.59; I2 = 22%), cardiac mortality (RR 0.86, 95% CI 0.39–1.93; P = 0.72; I2 = 51%), major procedure-related complications (RR 0.93, 95% CI 0.44–1.96; P = 0.55; I2 = 62%), cardiac tamponade (RR 0.57, 95% CI 0.25–1.29; P = 0.18; I2 = 30%), device embolization (RR 0.74, 95% CI 0.30–1.86; P = 0.53; I2 = 0%), vascular complications (RR 0.74, 95% CI 0.34–1.52; P = 0.38; I2 = 0%), or peridevice leak (RR 0.88, 95% CI 0.56–1.36; P = 0.55; I2 = 77%). WATCHMAN showed higher device thrombosis (RR 1.73, 95% CI 1.20–2.49; P = 0.003; I2 = 0%) but lower pericardial effusion (RR 0.47, 95% CI 0.29–0.76; P = 0.002; I2 = 0%). Conclusions: WATCHMAN and Amulet demonstrate no significant difference in efficacy and safety for most LAAC outcomes, including stroke and major bleeding. However, WATCHMAN is associated with a significantly lower risk of pericardial effusion but a higher risk of device thrombosis.