Predictive Value of the Fibrosis‑4 Index in TAVI Patients with Persistent Tricuspid Regurgitation

K. Mahmoud (Bonn)1, J. Shamekhi (Bonn)2, M. Al Zaidi (Bonn)2, P. Düsing (Bonn)2, H. Billig (Bonn)2, V. O. Vij (Bonn)2, E. Cekaj (Bonn)2, E. Markidis (Bonn)3, L. Al-Kassou (Bonn)2, A. Karaki (Bonn)2, A. Zietzer (Bonn)2, J. Vogelhuber (Bonn)2, M. Weber (Bonn)2, E. Lüsebrink (Bonn)2, G. Nickenig (Bonn)2, S. Zimmer (Bonn)2, B. Al-Kassou (Bonn)2
1Universitätsklinik Bonn Medizinische Klinik II Bonn, Deutschland; 2Universitätsklinikum Bonn Medizinische Klinik und Poliklinik II Bonn, Deutschland; 3Herzzentrum des Universitätsklinikums Bonn Medizinische Klinik und Poliklinik II Bonn, Deutschland
BACKGROUND
Concomitant tricuspid regurgitation (TR) is common in patients undergoing TAVI. Previous studies have reported increased mortality in TAVI patients with ≥moderate TR. Emerging evidence suggests that liver dysfunction contributes to adverse outcomes in TR. The Fibrosis-4 (FIB-4) index, a non-invasive marker of hepatic fibrosis, has been associated with adverse outcomes in heart failure and may reflect the hepatic impact of right-sided pressure overload. However, its prognostic value in TAVI patients with persistent TR remains unclear.

OBJECTIVE
We aimed to evaluate the clinical implications of the FIB-4 index in patients undergoing TAVI. Specifically, we sought to assess the predictive value of the index in TAVI patients with ≥moderate TR.

METHODS
The study included 1,797 patients undergoing TAVI. Echocardiography was performed at discharge and at 30-90 days post-procedure to determine the persistence of significant TR despite hemodynamic changes after valve replacement. The patients were stratified into low and high FIB-4 groups based on ROC curve analysis. The primary endpoint was one- and five-year mortality after TAVI.

RESULTS
The mean age of the population was 80.9±6.1 years, and 49.5% were female. Concomitant ≥moderate TR was observed in 348 (19.3%) patients. Patients with TR were significantly older (81.9±6.1 vs 80.7±6.0 years, p<0.01) and had lower left ventricular ejection fraction (52.4±12.7 vs 56.4±11.9%, p=0.01). Persistent TR was associated with higher creatinine (1.2 vs 1.1 mg/dL, p<0.01) and troponin levels (32 vs 25 pg/mL, p<0.01). Based on a cutoff value of 1.82, 42.1% of patients with TR were classified as having a low FIB-4 and 57.9% as having a high FIB-4 index. Compared with the low FIB-4 group, patients with a high FIB-4 index had higher rates of pulmonary hypertension (50.2% vs 40.8%, p<0.01), right ventricular dysfunction (37.4% vs 26.9%, p<0.01), and larger inferior vena cava diameter (1.7±0.6 vs 1.3±0.5 cm, p<0.01). One- and five-year mortality was higher in patients with ≥moderate TR compared to those with no/mild TR (17.8% vs 12.3%, p=0.01; 48.4% vs 36.8%, p<0.01, respectively, Fig 1). Kaplan-Meier analysis showed that a high FIB-4 index was associated with significantly higher one- and five-year mortality among patients with persistent ≥moderate TR (p<0.01; Fig 2). Multivariable analysis revealed that a high FIB-4 index was independently associated with mortality in patients with persistent TR (HR: 1.91 [95%CI: 1.07-3.42], p=0.01).

CONCLUSION
In patients undergoing TAVI, persistent ≥moderate TR is associated with adverse outcomes. Among these patients, a high FIB-4 index identifies a subgroup at particularly high mortality risk, independent of other clinical and echocardiographic factors. The index may serve as a useful tool for post-TAVI risk stratification, integrating the impact of hepatic dysfunction into the assessment.