Impact of left atrial appendage exclusion during mitral valve surgery: A systematic review and meta-analysis of comparative studies

STRUCTURED ABSTRACT Objective Several studies have evaluated left atrial appendage exclusion (LAAE) during mitral valve surgery (MVS); however, findings have been limited by small sample sizes, rarity of outcomes, and heterogeneous patient populations. We aimed to perform a meta-analysis of studies evaluating mortality and stroke after MVS with and without LAAE. Methods We systematically searched five databases: PubMed, Embase, Web of Science, Cochrane, and ClinicalTrials.gov. Eligible studies included randomized trials and comparative observational studies of adults undergoing MVS with LAAE. Studies without a non-LAAE control group, as well as those not reporting on mortality or stroke, were excluded. Results 19 studies were included in the meta-analysis. LAAE during MVS was associated with a 25% reduction in early ( ≤ 30-day) mortality (RR: 0.75; 95% CI: 0.59-0.96) and a 28% reduction in early stroke (RR: 0.72; 95% CI: 0.57-0.90). Such benefits persisted at longer-term follow-up, with a 19% reduction in late mortality (> 6-month) (RR: 0.81; 95% CI: 0.71-0.91) and a 29% reduction in late stroke (> 30-day) (RR: 0.71; 95% CI: 0.60-0.84). LAAE was not significantly associated with increased bleeding, and there was no evidence of effect modification by preoperative atrial fibrillation status for any of the outcomes. Conclusions LAAE during MVS is associated with improved short- and long-term outcomes in terms of stroke and mortality. Importantly, protective effects were observed in patients with or without preoperative atrial fibrillation. We therefore suggest considering routine LAAE during MVS.