Fibrosis-4 index reflects the severity of tricuspid regurgitation and patient prognosis in atrial fibrillation

Abstract

Aims: Atrial fibrillation is a prevalent disease with increased risk of tricuspid regurgitation (TR), which can worsen prognosis by causing right heart remodelling. Fibrosis-4 index (FIB-4), a composite marker originally developed for liver fibrosis, has been revealed of prognostic value in heart failure. We aimed to clarify the association between FIB-4 and the severity of TR as well as the prognosis.

Methods and results: We conducted a retrospective cohort study in a medical centre, identifying atrial fibrillation patients with complete biochemical and echocardiographic data for evaluation. Up to 4919 patients were included. The median age was 75 years, 60.0% (n = 2952) of patients were male, 40.8% (n = 2008) of patients had significant mitral regurgitation, 52.1% (n = 2564) of patients had significant TR, and 34.4% (n = 1691) had both. The median level of FIB-4 was 2.33. Using multivariable regression, a positive correlation was observed between significant TR and FIB-4. With a median follow-up duration of 3.9 years, mortality occurred in 2694 (54.8%) patients. The high FIB-4 group (>2.67) was associated with an increased risk of all-cause death (adjusted hazard ratio [aHR] 1.357, 95% confidence interval [CI] 1.183-1.555, p < 0.001) when compared with the low FIB-4 group (<1.3). In subgroup of isolated TR, high FIB-4 was also associated with significantly higher risks of all-cause mortality (aHR 1.930, 95% CI 1.330-2.801).

Conclusions: In patients with atrial fibrillation, FIB-4 was positively associated with TR severity and an increased risk of all-cause mortality. FIB-4 serves as a simple, non-invasive tool for prognostic stratification of TR and possible surrogate marker for timely intervention.

Keywords: Atrial fibrillation; Congestive liver; Heart failure; Liver fibrosis; Tricuspid regurgitation.