National Outcomes of Pediatric Patients Bridged to Heart Transplant With the Heartmate 3 Ventricular Assist Device.

Abstract

We evaluated the national outcomes of all pediatric patients bridged-to-transplant with the HeartMate 3 (HM3) (Abbott Corp) and compared the outcomes of those with congenital (CHD) vs acquired (AHD) heart disease. The United Network for Organ Sharing (UNOS) database was queried for all patients aged <18 years in the United States ever supported with HM3 and entered into UNOS up to December 2024. Univariable analyses were performed to assess baseline characteristics and posttransplant survival. A total of 254 patients aged <18 years in UNOS have been supported with HM3 in the United States and entered into UNOS up to December 2024, including 230 of 254 (90.6%) successfully bridged-to-transplant with HM3, 10 of 254 (3.9%) transplanted without HM3, and 14 of 245 (5.5%) not transplanted and removed from the waiting list. Overall waitlist mortality was 12 of 254 (4.7%). Of the 230 recipients successfully bridged-to-transplant with HM3, median age at listing and median weight at listing were 14.0 (interquartile range [IQR], 12.0-16.0; range, 7.0-17.0) years and 56.9 (IQR, 43.3-75.0; range, 16.5-141.0) kg, respectively. Median duration of support was 83.0 (IQR, 35.0-184.0) days. Left ventricular assist device (VAD),was the predominant VAD configuration (206 of 230, 89.6%) followed by biventricular assist device (20 of 230, 8.7%) and right VAD (4 of 230, 1.7%). Posttransplant rates of dialysis (17 of 230, 7.4%) and stroke (8 of 230, 3.5%) were low across the cohort. Aggregate 1-year posttransplant mortality was 7 of 230 (3.0), with survival estimates of 96.6% at 1 year (95% CI, 94.1%-99.1%), and 85.8% at 5 years (95% CI, 78.6%-93.6%). CHD patients had longer durations of HM3 support compared with AHD patients (141 [IQR, 59.0-235.0] days vs 76.0 [IQR, 33.0-167.0] days, P = .013). No difference was observed between CHD and AHD in 1-year posttransplant mortality (1 of 39 [2.6%] in CHD and 6 of 191 [3.1%] in AHD, P = .999) nor in 3-year posttransplant survival (90.6% [95% CI, 78.2%-99.9%] in CHD and 90.1% [95% CI, 84.9%-95.5%] in AHD, P = .828). HM3 is an effective bridge-to-transplant in larger pediatric patients, with equivalent long-term outcomes between CHD and AHD.