Pediatric heart transplant waiting list mortality in the era of ventricular assist devices.

BACKGROUND: Earlier reviews have reported unacceptably high incidence of pediatric heart transplant (PHT) waiting list mortality. An increase in ventricular assist devices (VAD) suggests a potential positive effect. This study evaluated PHT waiting list mortality in the era of pediatric VADs.

METHODS: United Network of Organ Sharing (UNOS) database from 1999 to 2012 showed 5,532 pediatric candidates (aged ≤ 18 years) actively listed for PHT: 2,191 were listed in 1999 to 2004 (Era 1) and 3,341 were listed in 2005 to 2012 (Era 2).

RESULTS: Waiting list mortality was lower in Era 2 (8%) vs Era 1 (16%; p < 0.001). VAD therapy was used more frequently in Era 2 (16%) than in Era 1 (6%; p < 0.001) and was associated with better waiting list survival (p < 0.001). There were more UNOS Status 1A patients in Era 2 (80%) vs Era 1 (68%; p < 0.001). Independent predictors of waiting list mortality included weight < 10 kg (odds ratio [OR], 2.7 95% confidence interval [CI], 1.1-6.9), congenital heart disease diagnosis (OR, 2.4; 95% CI, 1.9-3.0), blood type O (OR, 2.2; 95% CI, 1.8-2.8)], extracorporeal membrane oxygenation (OR, 1.5; 95% CI, 1.1-2.2), mechanical ventilation (OR, 1.8; 95% CI, 1.4-2.3), and renal dysfunction (OR 1.6; 95% CI, 1.2-2.0). Independent predictors of survival on the waiting list included VAD therapy (OR 4.2; 95% CI, 2.4-7.6), cardiomyopathy diagnosis (OR 3.3; 95% CI, 2.4-4.6), blood type A (OR, 2.2; 95% CI, 1.8-2.8), UNOS list Status 1B (OR, 1.9; 95% CI, 1.2-3.0), listed in Era 2 (OR 1.8; 95% CI, 1.4-2.2), and white race (OR 1.3; 95% CI, 1.1-1.6).

CONCLUSIONS: Despite an increase in the number of children listed as Status 1A, there was more than a 50% reduction in waiting list mortality in the new era. Irrespective of other factors, patients supported with a VAD were 4 times more likely to survive to transplant.