Among candidates listed for liver transplant (LT), MELD score may not capture acute on chronic liver failure (ACLF) severity. Data on interaction between ACLF and MELD score in predicting waitlist (WL) mortality are scanty.UNOS database (01/2002 to 06/2018) on LT listings for adults with cirrhosis and ACLF (without HCC) was analyzed. ACLF grades 1, 2, 3a, and 3b- were defined using modified EASL-CLIF criteria.Of 18,416 candidates with ACLF at listing (mean age 54 years, 69% males, 63% Caucasians), 90-d WL mortality (patient death or being too sick for LT) was 21.6% (18%, 20%, 25%, and 39% for ACLF grades 1, 2, 3a, and 3b respectively). Fine and Gray regression model identified interaction between MELD and ACLF grade, with higher impact of ACLF at lower MELD score. Other variables included candidate's age, gender, liver disease etiology, listing MELD, ACLF grade, obesity, and performance status. A score developed using parameter estimates from the interaction model on the derivation cohort (N=9181) stratified the validation cohort (N=9235) to four quartiles Q1 (score <10.42), Q2 (10.42-12.81), Q3 (12.82-15.50), and Q4 (>15.50). WL mortality increased with each quartile from 13%, 18%, 23%, and 36% respectively. Observed versus expected deciles on WL mortality in validation cohort showed good calibration (goodness of fit P=0.98) and correlation (R=0.99).Among selected candidates who are in ACLF at listing, MELD score and ACLF interact in predicting cumulative risk of 90-d WL mortality, with higher impact of ACLF grade at lower listing MELD score. Validating these findings in large prospective studies will support to factor in both MELD and ACLF in prioritizing transplant candidates and allocation of liver grafts.
View details for DOI 10.1016/j.jhep.2020.12.003
View details for PubMedID 33326814