Reconstructed Patient-Level Meta-analysis of Prophylactic Left Atrial Appendage Closure During Cardiac Surgery

The benefit of prophylactic concomitant left atrial appendage closure (LAAC) in cardiac surgery patients without preoperative atrial fibrillation is unclear. We aim to evaluate whether LAAC reduces the risk of late stroke in patients without preoperative atrial fibrillation.

A systematic search was conducted through July 2025 for studies investigating LAAC vs no LAAC in cardiac surgery patients without atrial fibrillation. Random-effects meta-analysis was performed, and Kaplan-Meier curves were digitized to reconstruct individual patient data. Primary outcome was stroke at 5 years. Median follow-up time was 3.8 years (interquartile range 2.1-4.6 years).

One randomised controlled trial and 6 observational studies were included with 4306 LAAC and 4129 no-LAAC patients. LAAC vs no-LAAC patients were similar in preoperative characteristics including age (66 vs 65 years; P = 0.8), sex (30% vs 29% female,-P = 0.8), and CHA₂DS₂-VASc scores (2.7 vs 2.6; P = 0.9). There was no difference in 30-day mortality (1.2% vs 1.1%, relative risk [RR] 1.04, 95% confidence interval [CI] 0.64-1.69; P = 0.42; I² = 0%). Postoperative atrial fibrillation was significantly higher after LAAC (31.1% vs 26.1%, RR 1.20, 95% CI 1.03-1.39; P < 0.01; I² = 72%). Using reconstructed patient level data, 5-year freedom from stroke improved after prophylactic LAAC (95.9% vs 94.4%, hazard ratio 0.66, 95% CI 0.52-0.83; P = 0.0004). The number needed to treat was 67 to prevent 1 stroke.

In patients without atrial fibrillation undergoing cardiac surgery, prophylactic LAAC was associated with a lower observed risk of stroke. These exploratory findings warrant confirmation in ongoing large multicentre randomised clinical trials.