Fibrosis-4 Index as an Independent Predictor of 1-Year Major Adverse Cardiovascular Events in ST-Segment Elevation Myocardial Infarction

Abstract

Objective: The Fibrosis-4 (FIB-4) index, derived from routine laboratory measurements, is a noninvasive marker increasingly linked to cardiovascular risk. However, its prognostic value in ST-segment elevation myocardial infarction (STEMI), particularly for composite outcomes, remains unclear. The objective of this study was to determine the independent predictive value of the FIB-4 index for 1-year major adverse cardiovascular events (MACE) in patients with STEMI. Methods: In this retrospective observational study, 1110 consecutive patients with STEMI treated with primary percutaneous coronary intervention were enrolled. The FIB-4 index was calculated on admission, and patients were grouped into tertiles. The primary outcome was 1-year MACE, a composite of all-cause death, reinfarction, and repeat revascularization. The association between FIB-4 index and outcomes was assessed using multivariable Cox regression and restricted cubic spline modeling. Results: One-year MACE occurred in 19.1% of the cohort. Event rates increased progressively across the FIB-4 tertiles (log-rank P < .001), with early and persistent divergence in Kaplan-Meier survival curves. In multivariable analysis, the FIB-4 index was independently associated with 1-year MACE; each 1-unit increment conferred an increased risk (HR, 2.02; 95% CI, 1.89-2.16; P < .001). Restricted cubic spline analysis demonstrated a nonlinear relationship, with risk rising more steeply at low-to-intermediate values before tapering at higher levels. Conclusions: Among patients with STEMI, the FIB-4 index was independently associated with adverse outcomes. Because it is simple and readily obtainable, it may add value to early risk assessment, although its incremental benefit over established risk models warrants further study.