Extracorporeal Membrane Oxygenation Support Before Pediatric Heart Transplantation: A Comparison of Two Eras

The United Network for Organ Sharing (UNOS) Database was studied to evaluate the state of extracorporeal membrane oxygenation (ECMO) utilization before pediatric heart transplantation and to compare outcomes over the last two decades. A total of 1,078 ECMO-supported pediatric patients (< 18 years at listing) were included in the final waitlisted cohort. Among these patients, 630/1,078 = 58.4% were in era 1 (2005-2014), and 448/1,078 = 41.6% were in era 2 (2015-2024). A total of 561/1,078 = 52.0% were transplanted, and total waitlist mortality (death or removal from waitlist due to clinical deterioration) was 376/1,078 = 34.9%. At all assessed timepoints, patients in era 2 demonstrated significantly higher waitlist survival compared to those in era 1, with survival estimates of 79.6% (95% confidence interval [CI] = 75.6-83.9%) vs. 65.6% (95% CI = 61.5-70.1%) at 1 month (log-rank p < 0.001). Additionally, listing in era 2 was protective of waitlist mortality (hazard ratio [HR] = 0.69; 95% CI = 0.57-0.85; p < 0.001). Among the 561 transplanted patients, 316/561 = 56.3% were transplanted in era 1, and 245/561 = 43.7% were transplanted in era 2. Overall posttransplant stroke rate was 8.1%, with no significant difference across era 1 and era 2 ( p = 0.466). Patients in era 2 had significantly better longitudinal posttransplant survival at 5 years (79.2% [95% CI = 73.7-85.2%] vs. 66.5% [95% CI = 61.5-72.0%], p < 0.001). In conclusion, ECMO support before transplantation is associated with lower waitlist mortality and improved long-term survival in the most recent decade.