Altered serum bile acid composition is associated with cardiac dysfunction in cirrhosis

Background: Elevated serum bile acids (BA) are harmful to the heart and alterations in the BA composition have been suggested to cause cardiovascular disturbances in cirrhosis. Aim: To investigate any associations between specific groups or individual serum BA and structural and functional cardiac abnormalities in patients with cirrhosis. Methods: An explorative study in 86 patients with cirrhosis. All participants underwent extensive cardiac assessment, including cardiac MRI with quantification of myocardial extracellular volume (ECV), which is indicative of diffuse myocardial fibrosis. A panel of 15 individual serum BA and C4, a marker of de novo bile acid synthesis, were assessed. Results: Patients with advanced cirrhosis had higher levels of total BA and conjugated BA, as well as lower C4 levels (p < 0.001). Conjugated BA levels were higher in patients with a high cardiac index (p < 0.001), increased left atrial volume index (LAVI) (p < 0.001), and in those with an abnormal myocardial ECV (p < 0.05). We also found several strong correlations between conjugated BA, both as a group and individually, and parameters of cardiac dysfunction. In a model adjusted for sex, age, BMI and MELD, conjugated BA remained significantly associated with LAVI, septal e', left ventricular volumes and cardiac index. In addition, taurocholic acid correlated closely with hepatic venous pressure gradient (HVPG) (p = 0.01). Conclusions: Increased serum concentrations of conjugated BA are associated with several cardiac parameters, indicating a potential role in the development of hyperdynamic circulation and cardiac dysfunction in cirrhosis. Moreover, taurine-conjugated BA are associated with portal hypertension.