NON-INVASIVE TESTS FOR FIBROSIS IN FONTAN-ASSOCIATED LIVER DISEASE ARE CONFOUNDED BY CONGESTION

BACKGROUND: Fontan-associated liver disease (FALD) is increasingly recognized as a serious complication post-Fontan resulting from the chronically elevated venous pressure created by this abnormal circulation. This study was designed to: define the prevalence and severity of FALD in our local population of pediatric (age <18 years) and adult Fontan patients, identify useful non-invasive screening tests for FALD and develop a longitudinal surveillance strategy. We hypothesized that severity of injury and fibrosis would correlate with time post-Fontan and that specific tests for fibrosis (including transient elastography, performed using FibroScan, and FibroTest, a score shown to correlate with the degree of liver fibrosis in viral hepatitis, calculated using ALT, GGT, haptoglobin, bilirubin, apolipoprotein A1, a-2-macroglobulin, age and gender) would be more sensitive and specific for FALD than standard ultrasound and routine laboratory investigations. METHODS: In this prospective cohort study, a total of 28 Fontan patients including 17 children (mean age 7.7 4 years, mean time post-Fontan 4.8 3.6 years) and 11 adults (mean age 31 7.7 years, mean time post-Fontan 22 3.7 years) provided informed consent to undergo liver ultrasound, FibroScan and bloodwork. RESULTS: In all patients studied the FibroTest (median 0.77, range 0.49-0.94, n1⁄415) and FibroScan (median 22.3 kPa, range 16.6-27, n1⁄46) were suggestive of cirrhosis regardless of time post-Fontan. In the adult Fontan group hemoglobin, CRP and GGT were significantly increased and platelet count and WBC were significantly decreased in comparison to the pediatric cohort. The INR was elevated above the normal range in both children (1.25 0.13, n1⁄410) and adults (1.33 0.48, n1⁄47). No patients with hepatocellular carcinoma were identified. Ultrasound-detected liver abnormalities did not correlate strongly with time post-Fontan. Agreement between investigations for the presence of FALD was poor. CONCLUSION: Liver-related abnormalities suggestive of FALD occur in both children and adults post-Fontan. The elevated CRP in the adult cohort suggests that Fontan physiology may contribute to a pro-inflammatory state. Interpretation of the FibroTest and FibroScan appears to be confounded by the presence of liver congestion with markedly abnormal results found in all patients regardless of time post-Fontan. We suggest that annual screening including CBC, GGT, INR, CRP, haptoglobin, bilirubin, a-fetoprotein and liver ultrasound may be useful for FALD surveillance. 271 ATRIAL FIBRILLATION IN ADULTS WITH CONGENITAL HEART DISEASE: SAME WINE IN DIFFERENT BOTTLE?