Abstract

The fibrosis-4 (FIB-4) index captures advanced hepatic fibrosis and cardio-hepatic congestion, but its prognostic merit in non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) relative to the newer fibrosis-5 (FIB-5) score is uncertain. In this single-centre retrospective cohort we evaluated 155 consecutive NSTE-ACS patients admitted between 2018–2022. FIB-4 index was dichotomised at the biopsy-validated threshold ≥3.25, whereas FIB-5 index was split at the cohort median –5.1. The primary composite end-point comprised all-cause death, heart-failure, acute kidney injury (AKI), rehospitalisation or revascularisation during a mean follow-up of 50±16 months. Multivariable logistic regression (adjusted for age and sex), receiver-operating-characteristic (ROC) analysis and interaction testing across diabetes, chronic kidney disease (CKD) and age ≥75 years were performed. Thirty-one patients (20 %) had FIB-4≥3.25. The composite end-point occurred in 64.5% vs 36.3% of high- and low-FIB-4 patients (p=0.006). FIB-4≥3.25 remained an independent predictor (adjusted OR 3.14, 95% CI 1.29-7.63; p=0.012) and out-performed FIB-5 (AUC 0.74 vs 0.58; p0.60). FIB-5 did not predict the composite or any individual component (p>0.30). An admission FIB-4≥3.25 triples the risk of mid-term mortality or major adverse events in NSTE-ACS, whereas FIB-5 is neutral. Incorporating FIB-4 into routine admission workflows could refine GRACE-based triage, spotlight extracardiac vulnerability and identify patients suited to intensified cardio-protective and decongestive strategies.

Key words: Fibrosis-4 index, Fibrosis-5 index, non-ST-elevation acute coronary syndrome, prognostic biomarkers, risk stratification