Waitlist Mortality and Recovery Among Pediatric Heart Transplant Candidates in Germany: A Nationwide Registry Analysis

Background Clinical outcomes of pediatric heart transplant candidates vary by region due to differences in donor availability and allocation policies. Most registry data originate from North America. We evaluated waitlist mortality, recovery, and associated risk factors among pediatric candidates in Germany. Methods All candidates < 18 years listed for heart transplantation in the German Transplant Registry (2006-2021) were retrospectively analyzed. Demographic and clinical predictors of mortality and recovery were assessed. Results Among 780 candidates, 441 (56.5%) underwent transplantation, 140 (17.9 %) died, 12 (1.5%) were withdrawn for deterioration, 61 (7.8 %) recovered, 42 (5.4%) were delisted for undocumented reasons, and 84 (10.8%) remained listed. Mean waiting time was 197 days, longest in children 1–10 years. Candidates that died or were removed were younger (median age 3.1 vs. 6.4 years, p=0.005), smaller, and more likely to have congenital heart disease (CHD, 32.2% vs. 21.3%, p<0.001). Waitlist mortality was higher in children < 2 years (HR 1.496) and in CHD (HR 1.702), while DCM was protective (HR 0.6312). Children < 2 years with diagnoses other than DCM had the highest waitlist mortality (HR 3.3). Recovery occurred in 7.8 %, mainly in infants < 1 year, with younger age and smaller height predicting improvement. ABO-incompatible transplantation was rare (8 cases) despite 278 (38.6 %) being <2 years at listing. Conclusion Waitlist mortality among pediatric candidates in Germany remains high, particularly in young children with CHD. Broader application of ABO-incompatible transplantation and systematic evaluation for recovery may improve outcomes under persistent donor shortage.