Clinical Outcomes of Left Atrial Appendage Occlusion During Cardiac Surgery in Patients Without Atrial Fibrillation: A Systematic Review and Meta-Analysis.

BACKGROUND: The left atrial appendage is the primary source of cardiac thrombi, and prophylactic exclusion during cardiac surgery may reduce thromboembolic risk. However, its benefit in patients without preoperative atrial fibrillation (AF) remains uncertain.

METHODS: We searched PubMed, Web of Science, EMBASE, and the Cochrane Library for randomized controlled trials and observational studies comparing surgical left atrial appendage occlusion (LAAO) versus no LAAO in patients with sinus rhythm undergoing cardiac surgery. Primary outcomes were new-onset transient ischemic attack (TIA)/stroke, postoperative AF, and all-cause death. Dichotomous outcomes were pooled as odds ratios and continuous outcomes as mean differences, with 95% CIs.

RESULTS: Eleven studies involving 12 145 participants were included. Compared with no LAAO, surgical LAAO reduced new-onset TIA/stroke (odds ratio, 0.75 [95% CI, 0.62-0.90]) and bleeding (odds ratio, 0.78 [95% CI, 0.60-1.00]) but increased postoperative AF (odds ratio, 1.27 [95% CI, 1.06-1.53]). No significant differences were detected between the 2 groups in all-cause death, 30-day death, and length of stay. Subgroup analyses showed some variation in effect estimates across study design, type of surgery, and LAAO technique.

CONCLUSIONS: In patients with sinus rhythm undergoing cardiac surgery, surgical LAAO was associated with a lower risk of new-onset TIA/stroke and bleeding but a higher incidence of postoperative AF, with no significant differences in all-cause death, 30-day death, or length of hospital stay. Study design, type of cardiac surgery, and LAAO technique may influence these associations. These findings should be interpreted cautiously given low to moderate certainty of evidence.