FIB-4 Index as a Non-Invasive Biomarker of Congestion and Prognosis in Heart Failure.

Liver involvement is closely related to the progression and prognosis of heart failure (HF). This review evaluates the role of FIB-4, a non-invasive and easily calculable index of hepatic fibrosis, as a prognostic biomarker across different HF phenotypes, compared with other established biomarkers of HF. Current evidence demonstrates that elevated FIB-4 scores are closely associated with systemic venous congestion and right ventricular dysfunction and represent a strong independent predictor of adverse cardiovascular events, particularly in HFpEF. In contrast, in HFrEF and HFmrEF, its prognostic value appears less pronounced and more strongly influenced by concomitant primary liver disease, such as MASLD. In acute heart failure, FIB-4 reflects congestion severity and its dynamic reduction during hospitalization carries independent prognostic significance. Compared with NT-proBNP, FIB-4 provides complementary or superior prognostic information in HFpEF, particularly in the presence of predominant right ventricular dysfunction. Additionally, FIB-4 may serve as a screening tool to identify subjects at risk for HFpEF. In conclusion, FIB-4 is a promising tool for risk stratification in HF. However, further prospective studies are needed to establish standardized cut-off values, support its incorporation into clinical guidelines, and clarify its response to SGLT2 inhibitor therapy. Moreover, emerging cardio-metabolic therapies targeting both HF and hepatic fibrosis may further increase the clinical relevance of FIB-4 as a dynamic biomarker of the cardio-hepatic axis.