Beneficial effect of left atrial appendage closure during cardiac surgery: a meta-analysis of 280 585 patients

In non-rheumatic atrial fibrillation (AF), left atrial appendage (LAA) is thought to be the source of embolism in 90% of the strokes. Thus, as recent clinical trials have shown the non-inferiority of percutaneous LAA closure (LAAc) in comparison to medical treatment, and despite a IIb recommendation in the latest guidelines for concomitant surgical LAAc, we sought to investigate the beneficial effect of LAAc in the surgical population. A meta-analysis model was performed comparing studies including any cardiac surgery with or without concomitant surgical LAAc reporting stoke/embolic events and/or mortality, from inception to January 2019. Twenty-two studies (280 585 patients) were included in the model. Stroke/embolic events both in the perioperative period [relative risk (RR) 0.66, 95% confidence interval (CI) 0.53-0.82; P = 0.0001] and during follow-up of >2 years (RR 0.67, 95% CI 0.51-0.89; P < 0.005) were significantly reduced in patients who underwent surgical LAAc (RR 0.71, 95% CI 0.58-0.87; P = 0.001). Regarding the rate of preoperative AF, LAAc showed protective effect against stroke/embolic events in studies with >70% preoperative AF (RR 0.64, 95% CI 0.53-0.77; P<0.00001) but no benefit in the studies with <30% of preoperative AF (RR 0.77, 95% CI 0.46-1.28; P=0.31). Postoperative mortality was also significantly lower in surgical patients with LAAc at the mid- and long-term follow-up. (RR 0.72, 95% CI 0.67-0.78; P<0.00001; I-2=0%). Based on these findings, concomitant surgical LAAc is associated with lower rates of embolic events and stroke in the postoperative period in patients with preoperative AF and also improves postoperative mortality in the mid- and long-term follow-up.