Changes in estimated glomerular filtration rate over the first year following repeat heart transplant in children and young adults.

Background: Renal function is reduced in patients undergoing heart transplant due to hemodynamic compromise, cardiorenal syndrome, and nephrotoxin exposure. No current studies evaluate renal function in retransplants. Methods: We reviewed all heart transplants at our center from 1995 to 2021 and matched first‐time heart transplants with retransplants, based on age at transplant, sex, and race. Estimated glomerular filtration rate (eGFR) was derived from CKiD‐U25 calculator using creatinine and measured prior to transplant, 1‐week post‐transplant, 1–3, 6, and 12 months post‐transplant, and recent follow‐up. Changes in eGFR were measured within and between patients using a piecewise linear mixed effect model with matching. Exploratory univariate analysis was performed to evaluate pre‐transplant risk factors for decreased eGFR. Results: The unmatched cohort included 393 heart transplant recipients, with 47 being retransplants. Thirty‐eight patients in both groups with at least 1 year of follow‐up underwent matching. Both retransplants and first‐time transplants had an initial decline in eGFR. eGFR rebounded to baseline or above baseline at 1–3 months post‐transplant, but eGFR in retransplants remained significantly lower. At 1‐year post‐transplant, the average eGFR was 67.8 ± 4.3 mL/min/1.73 m2 versus 104.7 ± 4.3 mL/min/1.73 m2 (p <.001) in the retransplants and first‐time transplants group, respectively. Conclusion: This study provides data on anticipated renal trajectory following retransplantation. [ABSTRACT FROM AUTHOR]