OBJECTIVES: The role of prophylactic concomitant left atrial appendage closure during mitral repair in patients without atrial fibrillation is not defined. The objective was to compare long-term outcomes of patients who had left atrial appendage closure during mitral repair with those who did not in patients without atrial fibrillation.
METHODS: A large national registry was used to identify 38,597 patients undergoing isolated mitral repair from 2010 to 2019. After excluding prior cardiac surgery, endocarditis, emergencies, and atrial fibrillation history, we identified 10,810 isolated mitral repairs. Of these, 1875 (17%) received closure and 8935 (83%) did not. Propensity score matching was performed on 27 baseline characteristics. The primary outcome of any stroke or thromboembolism was compared between matched groups using the cumulative incidence function in a Fine-Gray model with death as a competing risk. All-cause mortality was compared in a Cox proportional hazard model.
RESULTS: Propensity matching yielded 1875 well-matched patient pairs (mean age, 71 years, 45% female). New postoperative atrial fibrillation was more common in the closure group (45% vs 38.4%, P < .01). There was no difference in 30-day mortality (1.2% vs 1.1%, P = .88). There was a reduction in stroke and thromboembolism over 5 years (6.4% vs 8.3%, hazard ratio, 0.74, 95% CI, 0.57-0.96, P = .023). There was no difference in 5-year survival (91% vs 91%, hazard ratio, 0.99, 95% CI, 0.80-1.23, P = .95).
CONCLUSIONS: Left atrial appendage closure at the time of isolated mitral repair in patients without atrial fibrillation may be associated with increased incidence of postoperative atrial fibrillation, but reduced late stroke and thromboembolism compared with mitral repair alone.