Advanced liver disease in adults with Fontan circulation: a cross-sectional study from a tertiary center in Western Sweden.

BACKGROUND: Individuals with a univentricular Fontan circulation are at risk of developing Fontan-associated liver disease (FALD). This study aimed to determine its prevalence in adults with Fontan circulation in Western Sweden and to characterize the clinical and liver-related features of patients with and without significant FALD on imaging. METHODS: In this retrospective cross-sectional study (2019-2023) at a tertiary referral center, adults with Fontan circulation were identified through ICD codes. Ninety-six of 99 eligible patients were included (59.4% male; median age 26.5 years [IQR 21.5-31.0]). Clinical history, imaging, laboratory, and cardiopulmonary data were extracted from medical records. Patients were classified as FALD or non-radiologic FALD based on imaging (n = 86). Non-invasive fibrosis assessments (liver/spleen elastography, FonLiver score, FIB-4, APRI) were compared between patients with advanced FALD and portal hypertension (A-FALD) and other FALD cases. RESULTS: FALD was identified in 64 of 86 patients, including 42 with advanced fibrosis/cirrhosis. Median liver and spleen stiffness were 14.4 kPa [IQR 8.7-23.0] and 27.9 kPa [21.7-37.1], respectively. Patients with FALD had higher inferior vena cava pressure, BMI, spleen length, and prevalence of focal liver lesions (all p < 0.05). No hepatocellular carcinoma was detected. Within the FALD group, liver stiffness (16.6 vs 11.0 kPa), FonLiver risk score (-0.93 vs -1.63), and FIB-4 index (1.1 vs 0.8) were significantly higher in patients with A-FALD (all p < 0.05). CONCLUSION: Advanced FALD is highly prevalent in adults with Fontan circulation and associated with elevated central venous pressure. Structured liver surveillance using non-invasive tools is warranted from early adulthood.