Predictive value of the Fibrosis-4 index in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

Background: Liver dysfunction is associated with an increased risk of mortality after cardiac interventions. The Fibrosis-4 (FIB-4 index), a marker of hepatic fibrosis, has been associated with a worse prognosis in heart failure. The prognostic relevance of the index in patients undergoing transcatheter aortic valve replacement (TAVR) is unknown. The aim of this study was to evaluate the clinical implications associated with the FIB-4 index in patients undergoing TAVR.

Methods: Between May 2012 and June 2019, 941 patients undergoing TAVR were stratified into a low or high FIB-4 index group, based on a cutoff value that was determined according to a receiver operating characteristic curve predicting 1-year all-cause mortality.

Results: Patients with a high FIB-4 index (n = 480), based on the cutoff value of 1.82, showed higher rates of pulmonary hypertension (43.8% vs. 31.8%, p < 0.01), right-ventricular systolic dysfunction (29.5% vs. 19.2%, p < 0.01) and larger inferior vena cava diameter (1.6 ± 0.6 cm vs. 1.3 ± 0.6 cm, p < 0.01) than patients with a low FIB-4 index (n = 461). Furthermore, a high FIB-4 index was associated with a significantly higher cumulative 1-year all-cause mortality (17.5% vs. 10.2%, p < 0.01) and non-cardiovascular mortality (12.1% vs. 2.5%, p < 0.01), compared to a low FIB-4 index. Multivariable analysis revealed that a high FIB-4 index was independently associated with all-cause mortality (HR: 1.75 [95% CI: 1.18-2.59], p < 0.01).

Conclusions: A high FIB-4 index is associated with right-sided heart overload and an increased risk of mortality in patients undergoing TAVR. The FIB-4 index may be useful as an additional predictor of outcomes in these patients.