Impact of the fibrosis-4 index in patients with ST-elevated myocardial infarction.

Background: The fibrosis-4 (FIB4) index, a simple, noninvasive marker used for hepatic diseases, represents adverse outcomes. The aim of the present study was to evaluate whether the FIB4 index can predict adverse outcomes in patients with ST-elevation myocardial infarction (STEMI).

Methods: We investigated patients with STEMI who underwent primary percutaneous coronary intervention (PCI) and were alive at discharge. The cut-off FIB4 index at discharge was investigated using the survival classification and regression tree (CART) model to predict adverse outcomes. The primary outcome was all-cause mortality.

Results: Between January 2006 and December 2018, 1354 patients with STEMI (median age, 68 years; men, 76.1%) were investigated. The median value of the FIB4 index was 1.21 (0.84-1.78). The CART model divided the study population into low (FIB4 index <0.945; n = 435), intermediate (0.945 ≤ FIB4 index < 2.185; n = 692), and high (FIB4 index ≥2.185; n = 227) groups based on the significant predictive values for all-cause death. During a median follow-up period of 4.3 years, all-cause death occurred in 208 patients (15.4%). The Kaplan-Meier analysis showed a significant increase in mortality with higher FIB4 index values (log-rank, P < 0.001). The multivariate Cox regression model revealed that the FIB4 index was an independent risk predictor for all-cause death in patients with STEMI [low group as reference vs. intermediate group, hazard ratio: 1.975; 95% confidence interval (CI): 1.166-3.346; P = 0.011 and vs. high group, hazard ratio: 4.633; 95% CI: 2.549-8.418; P < 0.001].

Conclusions: The FIB4 index was associated with the risk of all-cause mortality in patients with STEMI who underwent primary PCI.