Methacetin Breath Test in Patients With Liver Disease Secondary to Heart Disease

The aim of this project is assess a non-invasive functional liver tests in patients with the Fontan circulation that may be used for prognostic purposes. Specifically, we aim to determine whether there are alterations in Methacetin Breath Test (MBT) in the Fontan patient and if so, whether it is related to conventional tests of liver and cardiac function. The hypothesis is that MBT CPDR 20 in the Fontan patient is abnormal as a result of alterations in liver perfusion, liver cell metabolic capability and transhepatic resistance secondary to hemodynamics unique to the Fontan as well as end-organ liver damage. Due to lack of robust biomarkers or other risk stratification schemes, we aim to determine whether there is prognostic value in hepatic MBT CPDR 20 in the Fontan patient. Aims - The aims of this study are three-fold: 1. To measure MBT parameter in a cohort of patients with Congestive (Dilated) Cardiomyopathy and a group of Fontan patients and compare results to published normal controls. 2. To explore any association between MBT parameter and clinical parameters already available, including Fontan hemodynamics as assessed by either of the following tests: cardiac catheterization, echocardiography, non-invasive imaging of the liver (CT or MRI), non-invasive assessment of liver stiffness (ARFI, MRE or Fibroscan), laboratory investigations, and clinical characteristics (i.e. age of patient, time since Fontan operation, type of Fontan etc.) within 12 months of the study. 3. To determine whether MBT is predictive of clinical outcomes: heart failure, clinically significant ascites, and time to transplant or death.