Mitral regurgitation after left ventricular assist device weaning for cardiac recovery or left ventricular assist device-related complications: A ventricular assist device wean recovery network report.

Abstract

Background: Durable left ventricular assist device (LVAD) support can reduce mitral regurgitation (MR) through ventricular unloading and reverse remodeling. Although improvement in MR during LVAD support is well described, the trajectory of MR after LVAD weaning due to cardiac improvement or LVAD-related complications has not been systematically studied.

Methods: Using the multicenter VAD Wean Registry, we identified 603 patients who underwent LVAD weaning due to either cardiac improvement or LVAD-related complications. The present analysis included 367 patients with less than moderate MR (grade <2) at the time of weaning and at least one echocardiographic follow-up assessment thereafter. The primary endpoint was moderate or greater MR (grade ≥2). MR was assessed at predefined echocardiographic follow-up timepoints: 1, 3, 6, and 12 months after weaning, then annually up to 10 years. The primary endpoint was defined as the first documentation of ≥2 MR at any of these timepoints. Kaplan-Meier analysis was used to estimate cumulative incidence, and Cox proportional hazards regression to identify independent predictors.

Results: Over a mean follow-up of 33.3 months, 75 of 367 patients (20.2%) developed ≥2 MR. The cumulative incidence was 13.2% at 1 year, 19.6% at 3 years, 26.0% at 5 years, and 36.0% at 7 years. Independent predictors of developing worsening MR included older age at weaning (HR 1.04 per year, 95% CI 1.02-1.06, p < 0.001), higher MR grade at original implantation (HR 1.58 per grade, 95% CI 1.17-2.12, p = 0.003), male sex as a protective factor (HR 0.56, 95% CI 0.32-0.98, p = 0.042), and complete device explantation (HR 1.69, 95% CI 1.00-2.86, p = 0.049). The indication for weaning (responder vs. partial responder) was not an independent predictor. Development of ≥2 MR was associated with higher mortality (40.5% vs. 19.5%, p = 0.013), more heart failure readmissions (68.9% vs. 25.6%, p < 0.001), and lower event-free survival (p < 0.001).

Conclusions: Moderate or greater MR after LVAD weaning is associated with progressive cardiac remodeling and adverse clinical outcomes. Future research is warranted to investigate whether interventions targeting the modifiable factors we identified being associated with the development of MR can further improve outcomes.