(P070) FONTAN ASSOCIATED LIVER DISEASE: TRENDS OVER TIME

Background: Fontan associated liver disease (FALD) is a relatively new and poorly understood complication of long-term single ventricle palliation. Surveillance by bloodwork and liver imaging is supported, but the correlation of these findings to clinical events is not well understood. This study sought to describe serial liver function changes in patients with a Fontan circulation from 2014-2020 and determine if these findings can be used to accurately predict adverse clinical outcomes.

METHODS AND RESULTS: This retrospective chart review included adult patients (age ≥18) who underwent a Fontan operation and were followed by a specialist clinic between 2014-2021. Annual bloodwork, including serum liver enzymes and the tumor marker alpha-fetoprotein (AFP), and liver imaging were analyzed to assess liver function. Common liver function scores were calculated, including a previously published imaging score (“liver imaging score”) wherein a score of 1 was assigned to normal imaging, 2 to minor changes including early fibrosis and arterial nodules, 3 for cirrhosis, and 4 for cirrhosis with enhancing nodules. Trends over time were assessed, as well as the incidence of and correlation to clinical events. Events were defined as congestive heart failure, cardiac hospitalization, cardiac intervention, thrombosis, protein losing enteropathy, and death.

One hundred twelve Fontan patients were included with a mean age of 25 ± 8 years and 67 (60%) were male. Extracardiac Fontan was the most common (46%) and the majority had a morphological left ventricle (73%).

Three patients were diagnosed with hepatocellular carcinoma and one patient died due to complications of metastatic disease. Age-adjusted AFP and creatinine increased over the study period, while ALP decreased (Table 1). The proportion of patients with higher liver imaging scores significantly increased over the study period.

Over a follow-up time of 6.1 years (95% CL 5.5,6.9 years), 44 patients (39%) experienced at least one event (2.6±1.9 events; Figure 1). The most common events were 64 cardiac hospitalizations followed by 24 congestive heart failure events. In multivariate analysis, age was associated with a greater risk of events (HR 1.035 [95%CI 1.008, 1.063; p=0.01); no other biomarkers or scores were significant.

Conclusion: Liver imaging suggests that FALD occurs in a subset of patients with a Fontan circulation, with increasing risk over time. However, improved standardized and sensitive measures are required to ensure adequate early diagnosis to support early treatment and avoid complications.