IgA class antineutrophil cytoplasmic antibodies in primary sclerosing cholangitis and autoimmune hepatitis.

OBJECTIVES

Body weight is still the most common metric used for donor-recipient matching in Pediatric Heart Transplantation (PHTX) and its impact on long-term outcomes remains unclear from variable definition and conflicting evidence. In this study, the outcomes of varying weight mismatch on PHTX was analysed.

METHODS

The United Network for Organ Sharing (UNOS) database (1984-2025) was retrospectively analysed. Size mismatch as a percentage donor-recipient weight difference was categorized as Mild (≤ 20%), Moderate (20-30%), Extreme (> 30%), and stratified as undersizing or oversizing. Demographics, clinical characteristics, and post-transplant outcomes were compared. One-year and 15-year mortality were analysed using multivariable logistic and Cox regression, respectively.

RESULTS

Oversizing (80%, 9,175/11,583) was more common than undersizing (20%, 2,408/11,583). With increasing oversizing, the recipients were younger, had congenital heart disease (CHD) diagnosis, and elevated pulmonary vascular resistance but with shorter wait-list times. Oversizing had no impact on 30-day, 1-year, or 15-years survival. With increasing undersizing, recipient age was similar, had less restrictive cardiomyopathy diagnosis, and had female donor but with shorter wait-list times. Undersizing had inferior survival till 5-years but not at 15-years. However, on multivariable analysis, undersizing was not predictive of inferior survival anytime as was congenital heart disease diagnosis, Extracorporeal Membrane Oxygenation (ECMO) bridge, elevated pulmonary-vascular resistance, transplantation era, and post-transplant rejection, stroke, and dialysis use.

CONCLUSIONS

Oversizing is more likely than undersizing in PHTX. While oversizing had no overall survival impact, undersizing had negative mid-term but not long-term survival impact which disappeared when adjusted for underlying cardiac diagnosis, elevated pulmonary vascular resistance, transplantation era and occurrence of post-transplant complications.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12055-026-02195-8.