Nguyen Thai Cuong, Le Xuan Duong, Nguyen Chi Tam, Nam Van Do, Ngo Dinh Trung
BACKGROUND Acute-on-chronic liver failure (ACLF) is associated with multiorgan failure and high short-term mortality. Liver transplantation (LT) can be lifesaving, but commonly used pretransplant severity scores were not developed to predict post-transplant mortality. This study compared AARC, CLIF-C ACLF, and MELD-Na for 90-day mortality after LT. MATERIAL AND METHODS This single-center observational cohort study included 78 consecutive patients aged 16 years or older with EASL-CLIF ACLF who underwent LT at the 108 Military Central Hospital between January 2022 and June 2025. All 3 scores were independently recalculated from a common pretransplant assessment. The primary outcome was 90-day all-cause mortality, and the primary score comparison was non-directional. Discrimination was assessed using AUROCs with stratified percentile-bootstrap confidence intervals and paired DeLong comparisons with Holm adjustment. Separate Firth logistic and Cox models evaluated associations per 1-standard-deviation increase. RESULTS HBV-related liver disease accounted for 62.8% of the cohort, and 89.7% underwent living-donor LT. Fourteen patients (17.9%) died within 90 days. CLIF-C ACLF had the highest numerical AUROC (0.755; 95% CI, 0.562-0.917), followed by MELD-Na (0.714; 0.550-0.854) and AARC (0.654; 0.491-0.799); no pairwise difference remained significant after Holm adjustment. A 1-standard-deviation increase in CLIF-C ACLF (11.05 points) and MELD-Na (6.17 points) was associated with higher 90-day mortality, whereas AARC was not. Sensitivity analyses produced similar findings. CONCLUSIONS CLIF-C ACLF showed the strongest numerical prognostic performance, but statistically significant superiority was not established. These scores should complement multidisciplinary transplant assessment.