Prognostic value of the FIB-4 index in patients with myocardial infarction with non-obstructive coronary arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous syndrome with non-negligible risk of major adverse cardiovascular events (MACE). The Fibrosis-4 (FIB-4) index, a non-invasive marker of hepatic fibrosis, has been linked to adverse cardiovascular outcomes, yet its prognostic relevance in MINOCA remains unclear. This study aims to evaluate the association between FIB-4 and long-term MACE in MINOCA.

We performed a single-center retrospective cohort study of consecutive MINOCA patients admitted from June 2020 to July 2025. The primary endpoint was MACE (composite of all-cause death, recurrent MI, stroke, and heart failure). Cox models were used to identify the predictors of MACE.

A total of 321 patients were included, with a median follow-up of 26.6 months (15.9, 36.2); 41 patients (12.8 %) experienced MACE. Multivariable Cox analysis showed that N-terminal pro-B-type natriuretic peptide (NT-proBNP) (HR = 1.67, 95 % CI 1.04-2.69, P = 0.035), diabetes mellitus (HR = 2.08, 95 % CI 1.08-4.03, P = 0.029) and FIB-4 (HR = 1.12, 95 % CI 1.04-1.20, P = 0.003) were independently associated with MACE. Restricted cubic splines suggested a significant nonlinear association between FIB-4 and MACE. FIB-4 demonstrated moderate discrimination for MACE (AUC = 0.758). Patients with FIB-4 > 2.63 had a significantly higher cumulative incidence of MACE than those with FIB-4 ≤ 2.63 (log-rank P < 0.001).

In patients with MINOCA, an elevated admission FIB-4 index is independently associated with long-term MACE and exhibits moderate discrimination.