Abstract 9709: Impact of Ventricular Assist Device Use on Pediatric Heart Transplant Waitlist Mortality: Analysis of the SRTR Database

Introduction: Children in need of heart transplant (Tx) have a high risk of death on the Tx waitlist due to scarcity of donor organs. Studies of previous eras have shown that ventricular assist devices (VADs) reduce waitlist mortality. We sought to determine whether a survival benefit for VAD patients persists in the current Tx allocation system. Methods: Using the Scientific Registry of Transplant Recipients database, we identified patients listed for primary Tx between 3/22/2016-9/1/2020. Characteristics at time of Tx listing were compared between VAD and non-VAD groups. Cox proportional hazards models were used to identify risk factors for one-year Tx waitlist mortality. Results: Among 5,054 total patients, 764 (15%) had a VAD at time of Tx listing. The VAD group was older, heavier, and had higher prevalence of cardiomyopathy, mechanical ventilation (MV), and impaired renal function. Unadjusted waitlist mortality was similar between the VAD and non-VAD groups (p=0.55, Figure), with the curves crossing ~90 days after listing. A multivariable Cox model showed infant age (HR 2.94, 95% CI 2.26-3.81), Black race (HR 1.59, 95% CI 1.33-1.90), congenital heart disease (HR 1.37, 95% CI 1.56-1.62), renal impairment (HR 2.62 95% CI 2.15-3.19), IV inotropes (HR 1.19, 95% CI 1.01-1.40) and MV (HR 2.58, 95% CI 2.13-3.13), were associated with one-year waitlist mortality. VAD use was not associated with mortality in the first 90 days after Tx listing (HR 0.87, 95% CI 0.65-1.18) but was protective for those waiting ≥90 days (HR 0.40, 95% CI 0.24-0.66). Conclusions: VADs reduce waitlist mortality in the current era, but only for those waiting ≥90 days after Tx listing. Potentially modifiable risk factors, including MV and renal impairment, are associated with mortality. These findings suggest that Tx listing without VAD may be a reasonable option if a short waitlist time is anticipated. However, VAD use may confer benefits, particularly for those expected to wait more than 90 days.