Mitral regurgitation at the time of left ventricular assist device implantation: Should it be treated or not?

Objective: Mitral regurgitation may persist or progress after left ventricular assist device implantation. However, whether preexisting mitral regurgitation should be corrected at the time of implantation remains to be determined. Methods: A retrospective, registry-based analysis was performed on 1398 continuous-flow left ventricular assist device recipients who underwent implantation between 2010 and 2022. Patients were compared for significant mitral regurgitation, defined as moderate-to-severe or greater mitral regurgitation after implantation, and major adverse events during left ventricular assist device support. Comparisons were made between patients untreated for mitral regurgitation but who had moderate or greater preexisting mitral regurgitation (n = 414) and those who had no or mild preexisting mitral regurgitation (n = 368) (cohort 1), and between patients with moderate or greater mitral regurgitation who underwent concomitant mitral valve surgery (n = 86) and those who did not (n = 414) (cohort 2). Results: The cumulative incidence of significant mitral regurgitation was higher in patients with untreated moderate or greater mitral regurgitation in both cohorts (P < .001 and P = .025, cohorts 1 and 2, respectively). However, the cumulative incidence of all-cause mortality and readmission, and the risk of other major left ventricular assist device complications such as stroke and right heart failure were comparable between groups in both cohorts. The results were also consistent for the propensity score–matched population created in each cohort. Conclusions: Significant mitral regurgitation may be prevented by concomitant surgery, but late survival and the risk of other major adverse events were not significantly improved by the procedure and were similar between patients with untreated moderate or greater mitral regurgitation and those with no or untreated mild mitral regurgitation. Our results suggest that mitral regurgitation during left ventricular assist device implantation may have only limited benefits from concomitant surgery.