Optimal pretransplant duration with HeartMate III left ventricular assist device: A contemporary analysis

Abstract

Background: This study evaluates the impact of pretransplant HeartMate III (HM3) left ventricular assist device (LVAD) support duration on post-transplant survival in a contemporary cohort.

Methods: A retrospective review of the United Network for Organ Sharing database was conducted for adult heart transplant recipients from January 2019 to December 2023 who were bridged with an HM3 LVAD. We utilized a restricted cubic spline fitted to a Cox proportional hazards model to stratify patients into duration groups based on risk inflection points (<1, 1-2, and >2 years), and outcomes were compared between and across groups.

Results: Among 1,996 patients, 35.2% (n = 702), 32.2% (n = 642), and 32.7% (n = 652) had support durations of <1, 1 to 2, and >2 years, respectively. Median support duration was 518 days [interquartile range: 289-864]. Postoperative rates of stroke and acute rejection did not vary across groups (p > 0.05); however, rates of postoperative dialysis significantly increased with increasing support time (p > 0.001). One-year survival was significantly higher for patients bridged <1 year (90.7% [95% confidence interval: 88.5-93.0]) compared to those bridged >2 years (84.3% [95% CI: 81.4-87.4], p < 0.001) but not for those bridged 1 to 2 years (89.0% [95% CI: 86.6-91.6], p = 0.300). In multivariable analysis, patients supported 1 to 2 years (hazards ratio: 1.34 [1.01-1.79], p = 0.045) and >2 years (hazards ratio: 1.77 [1.32-2.38], p < 0.001) had a higher hazard of post-transplant mortality than those bridged <1 year.

Conclusions: While the HM3 enables extended bridging to transplant, durations longer than 2 years of support are linked to worse post-transplant survival.

Keywords: VAD; heart transplant; mechanical circulatory support; transplant; ventricular assist device.