Waitlist Outcomes for Exception and Non-exception Liver Transplant Candidates in the United States Following Implementation of the Median MELD at Transplant (MMaT)/250-mile Policy.

Background: Since February 2020, exception points have been allocated equivalent to the median model for end-stage liver disease at transplant within 250 nautical miles of the transplant center (MMaT/250). We compared transplant rate and waitlist mortality for hepatocellular carcinoma (HCC) exception, non-HCC exception, and non-exception candidates to determine whether MMaT/250 advantages (or disadvantages) exception candidates.
Methods: Using Scientific Registry of Transplant Recipients data, we identified 23 686 adult, first-time, active, deceased donor liver transplant (DDLT) candidates between February 4, 2020, and February 3, 2022. We compared DDLT rates using Cox regression, and waitlist mortality/dropout using competing risks regression in non-exception versus HCC versus non-HCC candidates.
Results: Within 24 mo of study entry, 58.4% of non-exception candidates received DDLT, compared with 57.8% for HCC candidates and 70.5% for non-HCC candidates. After adjustment, HCC candidates had 27% lower DDLT rate (adjusted hazard ratio =  0.68 0.73 0.77 ) compared with non-exception candidates. However, waitlist mortality for HCC was comparable to non-exception candidates (adjusted subhazard ratio [asHR] =  0.93 1.03 1.15 ). Non-HCC candidates with pulmonary complications of cirrhosis or cholangiocarcinoma had substantially higher risk of waitlist mortality compared with non-exception candidates (asHR =  1.27 1.70 2.29 for pulmonary complications of cirrhosis, 1.35 2.04 3.07 for cholangiocarcinoma). The same was not true of non-HCC candidates with exceptions for other reasons (asHR =  0.54 0.88 1.44 ).
Conclusions: Under MMaT/250, HCC, and non-exception candidates have comparable risks of dying before receiving liver transplant, despite lower transplant rates for HCC. However, non-HCC candidates with pulmonary complications of cirrhosis or cholangiocarcinoma have substantially higher risk of dying before receiving liver transplant; these candidates may merit increased allocation priority.
Competing Interests: This work was supported by grants R01DK132395 (A.B.M.) from the National Institute of Diabetes and Digestive and Kidney Diseases and K24AI144954 (D.S.) from the National Institute of Allergy and Infectious Diseases. The other authors declare no conflicts of interest.
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