Abstract 4369227: Outcomes of Myocardial Recovery in Pediatric Patients Supported with Ventricular Assist Devices: A Multi-Center Analysis of the UNOS Registry

Background: Myocardial recovery on durable left ventricular assist device (LVAD) support is a rare but important and understudied outcome. The incidence and outcomes of LVAD explant for recovery in children listed for heart transplant (HT) are not well understood. Objective: To describe the incidence and outcomes of LVAD explant for myocardial recovery in children listed for HT. Methods: Using the United Network of Organ Sharing registry, this retrospective cohort study included pediatric patients (<18 years) who received a durable LVAD and were listed for HT between 2011 and 2023. Patients were tracked until death, HT, or explant for myocardial recovery. The cohort undergoing explant were followed for major adverse events (death, delisting due to clinical deterioration, transplantation, or re-implant of an LVAD) through December 31, 2024. Results: Among 1,894 pediatric LVAD recipients, explant for recovery was observed in 57 patients (3.0%) from 33 centers (42% of implanting hospitals). Median time to explant was 54 days (IQR, 16-113). Compared to those not explanted for recovery, these patients were younger (median age 1 year [IQR 0-1] vs. 5 [0-12], p=<0.001) and more often supported with inotropes (56.1% vs. 38.9%, p=0.02), mechanical ventilation (45.6% vs. 20.7%, p<0.001), and ECMO (14% vs. 5.9%, p=0.04) at listing. Freedom from major adverse events was 74% at 1 year with the greatest risk within the first 60 days of explant. One-year post-explant mortality was 7.0% (95% CI, 2.2-15.7%). ( Fig 1 ) Conclusions: LVAD explant for myocardial recovery is rare in pediatric patients listed for HT and is concentrated in fewer than half of implanting centers. However, 74% of explanted patients remained free of a major adverse event, and 1 year survival after explant for recovery was 93%. These data highlight the potential for recovery and underscore the need to identify predictors of successful explant to broaden this therapeutic option to additional patients.