A novel test called HepQuant® is an assay that has been used to measure liver function in other types of liver disease. In these populations, it is hoped that the assay may show more subtle or sub-clinical liver abnormalities that blood tests alone cannot detect. HepQuant® is a test that examines the ability of the liver to process a substance called cholate, which is a naturally occurring substance in the body. Cholate gets to the liver 2 ways: through the gut (by mouth) or through the blood (IV or intravenous). The test involves administering oral and IV cholate which is labeled. This label is NOT radioactive, but can act as an indicator/marker for evaluation purposes.
The purpose of this study is to develop a reliable means of measuring liver function in the Fontan survivor by examining cholate clearance. The investigators aim to 1) explore any association between level of cholate clearance and measurement of heart and liver function and 2) determine whether cholate clearance can predict clinical outcomes such as heart failure, ascites (development of fluid in the abdomen which can result from heart failure or liver failure), and need for heart transplant.
