US-CRS 2.0 index for heart transplant candidates: AUC 0.807 versus 0.693 for current system
Researchers in the US validated a heart transplant urgency index on waiting-list data; the results come from retrospective analysis and modeling, not from use in allocation.
Researchers in the United States developed and validated the US-CRS 2.0 medical urgency index for heart transplant candidates, ua.news reports, citing News-Medical and a study published in JAMA. According to the authors, the index distinguishes patients with a higher and lower short-term risk of death without transplantation more accurately than the current system with six priority statuses ua.news
ua.newsua.newsOpen source ↗. The analysis covered 33,097 adult candidates added to the US heart transplant waiting list between January 2019 and August 2025.
Model inputs and accuracy
The primary outcome was death or removal from the list due to worsening condition within six weeks without transplantation. The final simplified version of the model includes five laboratory indicators: albumin, bilirubin, estimated glomerular filtration rate, BNP or NT-proBNP, and sodium. It also takes into account four categories of mechanical circulatory support devices: an intra-aortic balloon pump, a durable left ventricular assist device, a microaxial pump, and ECMO or a temporary surgical ventricular assist device.
In the test sample, the AUC for the simple model was 0.807, compared with 0.693 for the current six-status system. A higher value indicates a better ability to distinguish candidates with a higher and lower risk of death. The researchers noted that patients with the same status in the current system may have substantially different prognoses even when using the same medical device.
Allocation modeling and limits
The authors also modeled the reallocation of 45,530 actual donor heart offers from 2019–2024. Under a scenario with US-CRS that retains the current allocation structure, observed six-week mortality among candidates first in line increased from 11.2% under the current system to 15.7%. With nationwide ranking by the index, this figure was 23.0% ua.news
ua.newsua.newsOpen source ↗.
The study does not establish how many deaths on the waiting list could actually be prevented and does not assess the effect of the new approach on post-transplant survival. The authors emphasize that full modeling is needed before possible implementation, including to ensure equitable access for patients with blood type O and people with durable left ventricular assist devices.
