Abstract
BACKGROUND: Acute-on-chronic liver failure (ACLF) is a life-threatening syndrome associated with high short-term mortality. Accurate risk stratification is crucial for the management of ACLF. AIM: To evaluate the prognostic value of the C-reactive protein to albumin ratio (CAR) and its dynamic changes in patients with ACLF defined by the Chinese Group on Study of Severe Hepatitis B (COSSH) criteria. METHODS: A total of 126 consecutive patients diagnosed with COSSH-ACLF were prospectively enrolled. CAR was calculated at admission and on days 4, 7, and 14. The primary and secondary outcomes were 28-day and 90-day mortality, respectively. Multivariate Cox regression analysis was conducted to identify independent predictors of mortality. A novel prognostic model (COSSH-CAR), integrating baseline and dynamic variables, was developed and compared with established prognostic scoring systems. RESULTS: The 28-day and 90-day mortality rates were 27.8% and 40.5%, respectively. Baseline CAR was significantly higher in 28-day non-survivors than in survivors (2.68 vs 1.42, P < 0.001). The dynamic change in CAR from baseline to day 7 (ΔCAR-7) showed stronger predictive power for 28-day mortality [area under the receiver operating characteristic curve (AUC) = 0.765] than baseline CAR (AUC = 0.698), ΔCAR-4 (AUC = 0.706) or ΔCAR-14 (AUC = 0.712). Multivariate analysis identified ΔCAR-7 (HR = 1.53), baseline Model for End-Stage Liver Disease-Sodium (MELD-Na) score (HR = 1.08), and hepatic encephalopathy grade (HR = 1.92) as independent predictors of 28-day mortality (all P < 0.05). The COSSH-CAR model, which incorporated these parameters, showed superior predictive performance (AUC = 0.832) for 28-day mortality compared with established prognostic scores, including Child-Pugh (AUC = 0.721), MELD-Na (AUC = 0.768) and COSSH-ACLF (AUC = 0.786) and effectively stratified patients into three risk categories with significantly different survival rates (P < 0.001). CONCLUSION: Dynamic changes in CAR during the first week provide important prognostic information in patients with COSSH-ACLF, surpassing baseline values and conventional inflammatory markers. The novel COSSH-CAR model improves risk stratification and may support clinical decision-making in the management of ACLF, pending external validation in diverse populations.