An analysis of more than 29,000 adults listed on the national heart transplant registry from 2006 to 2015 shows large discrepancies in how sick patients are when they receive heart transplants at hospitals across the country.
The rules give hospitals discretion in determining who gets a transplant.
Detailed in a new JAMA study, the analysis focuses on a metric called survival benefit, which is the difference between a patient's expected chance of survival after five years with a heart transplant versus without a transplant.
Survival benefit is scored as the percentage increase in their chance of survival. Over the study period, the average survival benefit for heart transplants ranged from 30% at so-called low survival benefit hospitals to 55% at high survival benefit centers. Roughly one quarter of the 113 transplant centers studied were low benefit centers, and one quarter were high benefit centers.
Of the patients who received a heart transplant, the overall survival rate after transplant was similar across all centers: about 77%. The findings suggest that the high survival benefit hospitals are prioritizing sicker patients first, giving organs to those with lower chances of survival without a transplant, and thus boosting their survival benefit to a greater degree.
Meanwhile, the study shows that the low survival benefit hospitals are playing it safe, giving organs to less critical patients who receive a smaller benefit from the transplant.
WHAT'S THE IMPACT
Until 2018, federal regulations required that hospitals rank heart transplant candidates on a three-tier scale from least to most medically urgent. But there's no lab test or physical measurement that can accurately rank patients in need of transplant. Instead, patients are assessed based on the intensity of treatment they receive. Patients on high-dose inotropic medications that increase the strength of muscular contractions to improve blood flow, or those who have received mechanical heart support devices like intra-aortic balloon pumps, are deemed the highest priority.
In a 2018 study published in the Journal of the American College of Cardiology, Dr. William Parker, lead author of the new research, and his colleagues showed how these rules incentivized hospitals to over-treat patients with more intensive therapies to boost their status for transplant.
The new study shows the downstream effects as transplant centers changed their practices to accommodate these rules. Transplant centers are scored by various state and federal agencies on their survival rates for patients one year after an organ transplant. While some hospitals would seem to be using the system as intended by prioritizing the sickest patients, this may encourage others to cherry pick candidates the program thinks will have an easy post-transplant recovery, and over treat them to boost their place on the waiting list.
In 2016, the Organ Procurement and Transplant Network, the federal agency that manages the donor organ allocation system, recognized these issues and recommended a new six-tier model for assessing patients in need of a heart transplant. The new rules were implemented in October 2018.
Researchers re-coded transplant candidates according to the new six-tier system, and found that, while it did introduce more balance in survival benefit across centers, it didn't account for ways that hospitals will likely change their practices to adapt to the new system. Its effects are yet to be seen.
The only reason hospitals have so much control over which heart patients get transplanted, authors said, is because the system relies on them to match treatments with the patients' severity of illness. In other organ allocation systems such as the liver, which uses an objective measure based on lab test values called the MELD score, hospitals don't have nearly as much discretion.