When patients awaiting crucial heart transplants are placed on the organ transplant waiting list, they've traditionally been arranged based on what type of treatments they were receiving for their current condition. But researchers from the University of Chicago have discovered a new, more accurate way to rank patients.
Published Feb. 13 in JAMA, the researchers conducted an observational study of patients registered on the U.S. heart allocation system between Jan. 1, 2019, and Dec. 31, 2022. Out of the 16,905 listed, 796 died waiting on a transplant during the study time period.
Because of the scarcity of heart donors and viable heart organs to use for performing the procedure, the U.S. Organ Procurement and Transplantation Network aims to order them by who needs it most, but the traditional method has not always been effective, according to the researchers. Typically, with the network's 6 status ranking system, the more intensive the treatment a patient is receiving will place them higher up on the list in terms of need-ranking.
However, the researchers note that "Despite a revision in Oct. 2018 that expanded the number of statuses, the current heart allocation system is susceptible to manipulation from overtreatment and exception requests, does not use important laboratory measures of illness severity and has only moderate predictive ability to rank order candidates according to medical urgency," they wrote. "It is also unclear how the categorical 6-status system will be implemented in the forthcoming continuous distribution system, which will require a medical urgency score."
The proposed new ranking method incorporates some of the methods of prediction that France uses for its own candidate risk assessment. Using it, researchers were able to outperform the original system and more accurately rank patients.
The "continuous multivariable allocation score outperformed the 6-status system in rank ordering heart transplant candidates by medical urgency and may be useful for the medical urgency component of heart allocation," they wrote.