Liver fibrosis marker is a potential predictor of the development of Fontan-associated liver diseases

To evaluate how well liver fibrosis markers (fibrosis-4 index, aspartate aminotransferase to platelet ratio index, and model for end-stage liver disease excluding international normalized ratio score) can predict early detection of Fontan-associated liver disease and to identify risk factors for Fontan-associated liver disease development. This retrospective multicentre study included patients who underwent the Fontan procedure between 2004 and 2020 with at least 3 years of follow-up. Blood tests and imaging were conducted to diagnose Fontan-associated liver disease. The predictive value of these markers was assessed using receiver operating characteristic curve analysis. Risk factors for Fontan-associated liver disease development were identified using Fine-Gray subdistribution hazard analysis. This study included 137 patients. The fibrosis-4 index, measured at 2 years post-Fontan, was a strong predictor for Fontan-associated liver disease development 10 years later (area under the curve: 0.81, optimal cutoff value: 0.17, 83.1% sensitivity, and 73.0% specificity). Fine-Gray subdistribution hazard analysis shows that a fibrosis-4 index level was a key risk factor for Fontan-associated liver disease. Patients with a fibrosis-4 index >0.17 after 2 years had a higher incidence of Fontan-associated liver disease after 10 years (45.6%) than patients with fibrosis-4 index ≤0.17 (3.9%, P = 0.002). These patients also had higher pulmonary artery pressure 5 years later. The fibrosis-4 may be a useful marker for early detection of Fontan-associated liver disease, which, in this study, was identified as a risk factor for the disease's development.