Epicardial Fat is Associated with Ventricular Dilation in Patients After the Fontan Operation.

Epicardial and hepatic fat are suspected to play a role in cardiac remodeling. The primary objective of this study was to identify the cardiac MRI (CMR) parameters that are associated with indexed epicardial fat mass (EFMi) and hepatic steatosis in patients after the Fontan operation. This was a single-center, retrospective analysis of Fontan patients. Epicardial and subcutaneous fat were analyzed with CMR post-processing software, cvi42 (Circle Cardiovascular Imaging, Calgary, Alberta, Canada). Hepatic steatosis was measured with controlled attenuation parameter (CAP) scores via vibration controlled transient elastography. The cohort included 82 patients (65% male, median age 16 years). On univariate analysis, EFMi correlated with BMI (ρ = 0.52, p < 0.001), age (ρ = 0.48, p < 0.001), ESVi (ρ = 0.44, p < 0.001), EDVi (ρ = 0.42, p < 0.001), ventricular massi (ρ = 0.41, p < 0.01), subcutaneous fat thickness (ρ = 0.32, p < 0.01), ejection fraction (ρ=-0.37, p < 0.001), and inferior vena cava (IVC) flowi (ρ=-0.26, p < 0.05). On multivariable regression analysis, BMI (β 2.21, p < 0.001) and EDVi (β 0.33, p < 0.001) were independently associated with EFMi (R2 = 0.51). On univariate analysis, CAP scores correlated with BMI (ρ = 0.54, p < 0.001), subcutaneous fat thickness (ρ = 0.49, p < 0.001), subcutaneous fat massi (ρ = 0.44, p < 0.001), age (ρ = 0.36, p < 0.01), EFMi (ρ = 0.36, p < 0.001), and ventricular massi (ρ = 0.24, p < 0.05). On linear regression analysis, BMI (β 6.6, p < 0.001) was independently associated with CAP scores (R2 = 0.27). Neither EFMi nor CAP was significantly associated with adverse clinical events. BMI is strongly associated with epicardial and hepatic fat distribution. Epicardial fat mass is also associated with ventricular dilation.