Fewer children waiting for a heart transplant are dying, but it is due to medical care improvements rather than changes to organ allocation, a recent study led by researchers at Stanford (Calif.) Medicine study found.
The study, published in the Journal of the American College of Cardiology, analyzed data from all 12,408 U.S. children who were listed for heart transplants between Jan. 20, 1999, and June 26, 2023. The team compared how transplant candidates were actually ranked on the waitlist with how they would be ranked if the listing order was based on medical urgency. They also considered whether improvements in waitlist outcomes aligned chronologically with allocation changes implemented in 2006 and 2016.
The current waitlist has three categories: 1A, the most urgent status, then 1B and 2. Factors used to determine a child’s category include the type of heart problem and medications they are receiving.
Here are five study findings:
1. Patients’ risk of dying on the waitlist fell from 21% to 13%. However the decline in deaths was due to medical care improvements rather than organ waitlist allocation.
“Wait-list mortality, which is the chance that a child will die while awaiting transplant, is higher in pediatric heart transplant than for virtually any other organ or age group,” the study’s senior author, Christopher Almond, MD, a professor of pediatrics at Stanford Medicine, said in a March 11 news release from the health system.
2. Pediatric heart transplant candidates who received exceptions to advance up the waitlist were not as sick as children who met standard criteria for the same waitlist category.
3. The medical status of each child within the three categories on the waitlist varied widely. There was significant overlap in the risk of mortality in children categorized as priority 2; meanwhile, some children in the 1A status were not as sick. This means some children who are less sick received donor hearts instead of sicker children, researchers said.
“The current system is not doing a good job of capturing medical urgency, which is one of its explicit goals,” the study’s co-lead author, economist Kurt Sweat, PhD, said in the release.
4. Waitlist rule changes in 2006 and 2016 were not linked to improvements in mortality. Instead, the team found mortality decreased gradually from 1999 onward, driven by advancements such as ventricular assist devices and better recognition of when children should be added to the list.
5. The study authors recommend that the waitlist system should be revised to account for a broader range of medical factors and should use the combination of factors to assign each child a numeric risk score to replace the current three categories.
