Impact of the Donor Sequence Number on Outcomes and Survival in Pediatric Heart Transplant Patients

High donor sequence number (DSN) donor hearts are often regarded as low quality, despite studies suggesting otherwise, and thus declined. There is a paucity of literature on high DSN transplant outcomes in the pediatric population, especially after the 2016 allocation policy changes. We evaluated the impact of the DSN on outcomes in pediatric heart transplant patients in the contemporary era.

Demographic and outcome data were obtained from January 1, 2010, to September 29, 2024, from the Potential Transplant Recipient and Standard Transplant Analysis and Research databases. Patients ≥18 years, any repeated heart transplants, multiorgan transplants, and those without adequate follow-up data were excluded. DSNs were classified into "bins" (1-5, 6-10, 11-20, and >20) and by >80th and >95th percentiles for each calendar year.

Of the included 6279 patients, distribution across DSN bins was as follows: 1 to 5, n = 5181 (82.5%); 6 to 10, n = 616 (9.8%); 11 to 20, n = 314 (5.0%); and >20, n = 168 (2.7%). Mean DSN ranged from 3.10 to 6.38 in 2013 and 2020, respectively (P < .001). Comparing DSN >20 and 1 to 5 recipients, DSN >20 recipients were on average older (9.25 vs 6.74 years; P < .001), spent fewer days at status 1A (32.45 vs 69.67 days; P < .001), and had greater organ ischemia time (4.32 vs 3.58 hours; P < .001). Even after covariate adjustment, the DSN did not have an impact on mortality at 30 days, 1 year, and 5 years after transplant.

The DSN alone does not independently affect short- and long-term mortality after a pediatric heart transplant and should not be used alone to reject an offer.