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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

HM3 is an effective bridge-to-transplant in larger pediatric patients, with equivalent long-term outcomes between CHD and AHD.