Etiology-Specific Effects of Impaired Functional Status on Liver Transplant Outcomes

Pre-liver transplant (LT) functional status is an important determinant of prognosis post LT. There is insufficient data on how functional status affects outcomes of transplant recipients based on the specific etiology of liver disease. We stratified LT recipients by etiology of liver disease to evaluate the effects of functional status on post-LT prognosis in each subgroup.

2005-2019 United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) was used to select patients with liver transplant. A total of 14,290 patients were included in the analysis. These patients were stratified by functional status according to Karnofsky Performance Scale (KPS) score: no assistance, some assistance, or total assistance. They were then further divided into six diagnosis categories: metabolic dysfunction-associated steatotic liver disease (MASLD), hereditary disorders, hepatitis C, hepatitis B, autoimmune disease (AID), and alcoholic liver disease (ALD). Primary endpoints included all-cause mortality and graft failure, while secondary endpoints included organ-specific causes of death. Those under the age of 18 and those with non-whole liver or prior liver transplantation were excluded.

Patients with MASLD requiring some assistance (aHR: 1.57, 95% CI 1.03-2.39, p = 0.04) and those requiring total assistance (aHR: 2.32, 95% CI 1.48-3.64, p < 0.001) had higher incidences of graft failure compared to those requiring no assistance. Those with MASLD requiring total assistance had a higher all-cause mortality rate than those needing no assistance (aHR: 1.62, 95% CI 1.38-1.89, p < 0.001). Patients with hereditary causes of liver disease showed a lower incidence of all-cause mortality in recipients needing some assistance compared with those needing no assistance (aHR: 0.52, 95% CI 0.34-0.80, p = 0.003). LT recipients with hepatitis C, AID, and ALD all showed higher incidences of all-cause mortality in the total assistance cohort when compared to the no assistance cohort. For the secondary endpoints of specific cause of death, transplant recipients with MASLD needing total assistance had higher rates of death due to general cardiac causes, graft rejection, general infectious causes, sepsis, general renal causes, and general respiratory causes.

Patients with MASLD cirrhosis demonstrated the worst overall outcomes, suggesting that this population may be particularly vulnerable. Poor functional status in patients with end-stage liver disease from hepatitis B or hereditary disease was not associated with a significantly increased rate of adverse outcomes, suggesting that the KPS score may not be broadly applicable to all patients awaiting LT.