Oversizing Donors - Is It Necessary for ACHD Patients?: An Analysis of the United Network for Organ Sharing Registry

Purpose Orthotopic heart transplantation (OHT) among adult congenital heart disease (ACHD) patients triggers debate as to optimal donor sizing. Outcomes related to donor-to-recipient size ratios have never been analyzed in the ACHD population. Methods We conducted a retrospective cohort analysis of adults with ACHD undergoing OHT in the USA from January 1, 2000 to June 30, 2017 using the United Network for Organ Sharing (UNOS) registry. Univariate and multivariate analyses were performed to compare survivors versus those deceased at last follow-up. Chi-squared and Wilcoxon rank sum tests were used for categorical and continuous variables, respectively. Cox proportional hazard modeling was performed for time to death, cardiac graft failure, and post-OHT dialysis to assess the effects of donor-to-recipient ratios of height, weight, BMI, and LV mass ratios using a priori selected covariates. Results 827 patients met inclusion criteria and were analyzed. At a median follow-up of 1,462 days, there were 279 (33.7%) deceased ACHD OHT recipients. Renal dysfunction, ischemic time, and gender mismatch were all significantly associated with death and graft dysfunction using multivariate survival analysis. However, donor-to-recipient ratios of height, weight, BMI, and LV mass were not associated with the outcomes of interest. Conclusion This study is the first to show that ACHD patients undergoing OHT do not have differential survival based on donor sizing. Survival and freedom from graft dysfunction among ACHD patients undergoing OHT is similar to the non-ACHD population and is associated with reduced ischemic times, a lack of gender mismatch, and a lack of pre- and post-operative renal dysfunction. Our findings demonstrate that intentional donor oversizing in the ACHD population as a protective measure against post-operative right ventricular dysfunction does not reduce mortality, decrease risk of graft dysfunction or post-OHT need for dialysis.