Assessing Donor-Recipient Size Mismatch in Pediatric Heart Transplantation: Lessons Learned From Over 7,500...

Area of Science:

• Cardiology
• Transplantation Medicine
• Pediatric Surgery

Background:

• Optimal donor-recipient (D-R) size matching in pediatric heart transplantation (HT) remains unidentified.
• Current metrics lack standardization, impacting graft survival and patient outcomes.

Purpose of the Study:

• To identify size mismatch metrics that accurately predict graft survival post-pediatric heart transplantation.
• To evaluate the impact of various D-R size parameters on graft survival and morbidity.

Main Methods:

• Analysis of 7,715 D-R pairs from the Pediatric Heart Transplant Society database (1993-2021).
• Evaluation of size mismatch (height, weight, BMI, BSA, P-H-M, TCV) effects on 1- and 5-year graft survival and morbidity.
• Utilized Cox models with stepwise selection to identify independent predictors of graft survival.

Main Results:

• Total cardiac volume (TCV) and height were the only size metrics predicting graft survival at 1 and 5 years.
• Nonlinear effects of D-R size mismatch observed; undersizing by height increased graft loss and rejection.
• Minimal donor undersizing by TCV was protective, while oversizing up to 25% showed no increased graft loss.

Conclusions:

• Total cardiac volume (TCV) is the most optimal metric for D-R size matching in pediatric HT.
• Standardizing D-R size matching using TCV and height can improve graft survival and reduce donor organ discard.