Mortality and Stroke After Routine Left Atrial Appendage Occlusion in Patients Undergoing Isolated Mitral Repair Without Atrial Fibrillation in the United States

In this study, the authors compared the long-term outcomes of patients who underwent left atrial appendage closure during mitral repair with those who did not, specifically in patients without atrial fibrillation (AF). The analysis included 10,810 patients from a large US national registry who underwent isolated mitral repairs. Of these, 1,875 (17 percent) received closure, while 8,935 (83 percent) did not. Propensity score matching was performed based on baseline characteristics. The primary outcome of any stroke or thromboembolism was compared between matched groups, with death considered as a competing risk. All-cause mortality was also compared. 
 
Propensity matching yielded 1,875 well-matched patient pairs (mean age: 71 years, 45 percent female, median CHA2DS2-Vasc score 3.0). New post-operative AF was more common in the closure group (45 percent vs 38.4 percent, p<0.01). There was no difference in 30-day mortality (1.2 percent vs 1.1 percent, p=0.88). The closure group demonstrated a reduction in stroke and thromboembolism over five years (6.4 percent vs 8.3 percent, HR: 0.74, 95 percent CI: 0.57-0.96, p=0.023). However, there was no difference in five-year survival rates (91 percent vs 91 percent, HR: 0.99, 95 percent, CI: 0.80-1.23, p=0.95). 
 
The authors concluded that left atrial appendage closure at the time of isolated mitral repair in patients without AF may be associated with an increased incidence of postoperative AF, but it also appears to reduce the risk of late stroke and thromboembolism compared to mitral repair alone.