Abstract 15790: Neurologic Impact of Left Atrial Appendage Exclusion in Mitral Valve Surgery, a Retrospective Study

Context: Up to 40% of patients undergoing isolated mitral valve surgery develop atrial fibrillation (AF). AF is a significant risk factor for stroke and 90% of clots responsible for AF-related neurological events form in the left atrial appendage (LAA). LAA exclusion (LAAe) could potentially reduce post-operative neurological complications in patients undergoing mitral valve surgery. Methodology: Single center retrospective cohort study with prospectively collected data including all patients undergoing mitral valve surgery between January 2003 and April 2014. Univariate analysis and multivariate analysis with stepwise approach were performed. Results: Results were obtained for 2728 patients who met the inclusion criteria. Of these, 406 (14.9%) had a LAAe. This group of patients suffered more frequently from pre-operative AF (86.7% vs 35.1%, p<0.0001) and had more concomitant Maze procedures (78.3% vs 12.3%, p<0.0001) than the group of patients who did not have LAAe (n-LAAe). By univariate analysis, in-hospital mortality was comparable in the LAAe vs n-LAAe groups (4.7% vs 6.5%, p=0.18). The risks of post-operative stroke (3.0% vs 3.5%, p=0.77) and transient ischemic attack (0.5% vs 0.4%, p=0.70) were also comparable. No difference in reoperation for bleeding between the two groups was observed (5.9% vs 6.8%, p=0.59). By univariate analysis, the presence of AF (pre- or post-operative) did not have a significant impact on mortality (p=0.48 and p=0.89, respectively). There was a significant difference in long-term survival between the LAAe group and the n-LAAe group (p=0.0007, median follow-up 2.4 years). By multivariate analysis, LAAe was identified as an independent protective factor from long-term mortality [OR 0.47; CI95% (0.25-0.89)]. The performance of an isolated Maze procedure [OR 0.66; CI95% (0.36-1.21)] did not have a significant impact on mortality. Conclusion: LAAe during mitral valve surgery is an independent protective factor from long-term mortality, without increasing peri-operative risks of bleeding or new onset AF. However, LAAe does not protect from neurologic events in the peri-operative period. Unlike LAAe, an isolated Maze procedure did not have an impact on long-term survival.