Clinical Characteristics and Outcomes of High-Cost Pediatric Heart Transplant Hospitalizations in the United States

Introduction: Pediatric heart transplantation (HT) is resource-intensive, with the HT hospitalization being a major driver of costs. We sought to determine the characteristics and outcomes of patients whose HT hospital admissions incur high costs. Methods: The Pediatric Health Information System database was queried for pediatric (<18 y) hospital admissions between 1/1/2008 and 12/31/2021 in which HT was performed. High-cost HT admission was defined as ≥95 th percentile of cost for all HT admissions during the study period. Costs were standardized across centers using a cost-to-charge ratio; all cost values (in US dollars) were indexed to the 2020 US Consumer Price Index. The primary outcome was mortality during the index HT admission. Clinical characteristics and outcomes were compared between high-cost HT admissions and lower-cost HT admissions (<95 th cost percentile) using logistic regression. Results: A total of 4352 pediatric HTs were identified; for the entire cohort, median HT admission cost was $501,535 (IQR $270,291 - $902,302). Within the high-cost group (N = 217), HT admission costs ranged from $1,971,069 - $44,500,000; the majority (N = 195) had costs between $2 million and $5 million. High-cost admissions accounted for 23% of costs within the entire cohort. Median length of stay in the high-cost group was 247d (IQR 160d-342d) and 59d (IQR 24d-115d) in the lower-cost group (P<0.001). High-cost HT admissions increased over time (2.9% of admissions in 2008; 5.5% in 2021, P<0.001). Patients with high-cost HT admissions were younger (1y vs 6y, P<0.001), more likely to have single ventricle congenital heart disease (42.4% vs 28.9%, P<0.001), undergo ECMO (55.3% vs 19.3%) and/or VAD (37.3% vs 16.2%, P<0.001 for both), and receive dialysis (13.8% vs 3.6%, P<0.001). Hospital mortality was higher in high-cost HT patients (22.6% vs 4.2%, P<0.001); this relationship persisted after adjusting for clinical and center characteristics (OR 7.2, 95% CI 4.97 - 10.57, P<0.001). Conclusions: High-cost admissions for pediatric HT contribute disproportionately to overall hospital mortality and cost after HT, and are associated with high resource utilization. These findings highlight opportunities to improve outcomes in this growing and high-risk population.