Overall waitlist mortality for children awaiting heart transplant improved from 25% in 2001 to 14% in 2011. However, the sickest children, including those on extracorporeal membrane oxygenation or a ventilator at listing, have not seen dramatic declines in waitlist mortality.
Using data from the Organ Procurement and Transplant Network, researchers examined 5,430 children aged younger than 18 years who were on a waiting list for a heart transplant from 2001 to 2011. Of those, 647 were on extracorporeal membrane oxygenation (ECMO) support. The results were presented at the International Society for Heart and Lung Transplantation Annual Meeting and Scientific Session.
According to results, waitlist mortality for pediatric patients not on invasive support declined 61%, from 18% in 2001 to 7% in 2011 (P<.01). Patients on ECMO support did not see a significant change in waitlist mortality during the study period (45% in 2001 vs. 41% in 2011; P=.89), whereas there was a larger decline, although nonsignificant, for mortality among patients on ventilator support (33% in 2001 vs. 26% in 2011; P=.15).
Baseline characteristics and number of patients (mean, 59 per year) on ECMO support at listing did not change appreciably from 2001 to 2011.
“The advances in ventricular assist device technology has contributed significantly to improving the overall pediatric heart transplant waitlist mortality in the United States; however, waitlist mortality for children listed from extracorporeal membrane oxygenation has not changed dramatically,” Christopher S. Almond, MD, assistant professor of pediatrics at Boston Children’s Hospital, said in a press release. “The biggest question is: Why are the sickest children not benefiting more obviously from recent technology advances? Do we simply need more time and patients to detect changes that are gradual and may become statistically significant in the future? This emphasizes the challenges of patient selection.”
For this study, waitlist mortality was defined as death while waiting or de-listing due to clinical deterioration, according to the abstract.