Abstract
INTRODUCTION: The Fibrosis-4 (FIB-4) index, a non-invasive marker of liver fibrosis originally developed for non-alcoholic fatty liver disease (NAFLD), has gained attention for its prognostic value in cardiovascular disease. AIM: Given the shared metabolic risk between NAFLD and acute coronary syndrome (ACS), this study aimed to evaluate the association between FIB-4 and major adverse cardiovascular events (MACE) in patients with ACS, in comparison with conventional risk scores. MATERIAL AND METHODS: This is an observational cohort study included 941 patients hospitalized with ACS between 2017 and 2021. Patients were classified into three FIB-4 categories: low, < 1.45; intermediate, 1.45-3.25; and high, ≥ 3.25. Clinical, laboratory, angiographic, and echocardiographic data were collected. MACE incidence was evaluated over a median follow-up of 67.5 months. Cox regression and receiver operating characteristic (ROC) analyses were performed. RESULTS: MACE occurred in 37.9% of patients in the high FIB-4 group, compared to 28.7% and 29.2% in the low and intermediate groups, respectively (p = 0.046). FIB-4 was an independent predictor of MACE (hazard ratio [HR]: 1.547; 95% CI: 1.169-2.046; p = 0.002). ROC analysis demonstrated superior prognostic accuracy for FIB-4 (area under the ROC curve: 0.693) over SYNTAX (0.609) and GRACE (0.552) scores. A Kaplan-Meier analysis showed significantly lower survival in the high FIB-4 group (p = 0.007). CONCLUSIONS: The FIB-4 index is a robust, accessible predictor of adverse cardiovascular outcomes in ACS and may enhance conventional risk stratification strategies by integrating systemic metabolic burden into cardiovascular risk assessment.