Validation of Congestive Hepatic Fibrosis Score in Pediatric and Adult Fontan-Associated Liver Disease

Fontan-associated liver disease is a unique form of congestive hepatopathy occurring after Fontan palliation of single functional ventricle congenital heart disease. Although congestive hepatic fibrosis post-Fontan has been scored with various histologic systems, none have been validated in this population. The Congestive Hepatic Fibrosis Score (CHFS) was developed to assess liver disease in congestive hepatopathy secondary to chronic right heart failure and is a promising tool for staging congestive hepatic fibrosis post-Fontan. We sought to validate the CHFS in this setting and to examine clinical, laboratory, and hemodynamic parameters impacting the development of Fontan-associated liver disease. Three pathologists reviewed liver biopsies from 42 pediatric and adult post-Fontan patients, with review of clinical, laboratory, and hemodynamic parameters. CHFS and METAVIR fibrosis scores divided biopsies into identical clusters of low stage (stages 0, 1, and 2) and high stage (stages 3 and 4) fibrosis. Interobserver variability for both scores was moderate. Patients with high-stage fibrosis had significantly longer mean time since Fontan. Female patients were more likely to have high-stage fibrosis. Hemodynamic variables had no significant differences between the groups. We conclude that CHFS is a valid scoring method in pediatric and adult patients post-Fontan. Time since Fontan is the best predictor of severe hepatic fibrosis, but much interpatient variation is not explained by any of the identified clinical, laboratory, or hemodynamic parameters. Liver biopsy, therefore, remains the best means of assessing liver fibrosis in post-Fontan patients.