Abstract 11739: Cardiac Magnetic Resonance Imaging Derived Inferior Vena Cava Cross-Sectional Area Correlates With Measures of Fontan Associated Liver Disease

Background: There is currently no clear consensus on appropriate screening techniques to evaluate the presence or severity of Fontan-associated liver disease (FALD). Cardiac MRI (CMR) is used routinely for post-Fontan surveillance, but CMR-derived measures that relate to the severity of FALD are yet to be defined. Methods: This was a cross-sectional single-center study of post-Fontan patients who underwent a CMR. CMR exams were re-analyzed by a single pediatric cardiologist. The inferior vena cava cross-sectional area (CSA) was measured on CMR and indexed to height (indexed IVC-CSA). Other CMR measurements included ventricular volumes and systolic function, ascending aorta flow, Fontan CSA, and pulmonary artery CSA. Surrogates of FALD included Gamma-Glutamyl Transferase (GGT), Fibrosis-4 laboratory score (FIB-4), and imaging findings. Findings consistent with cirrhosis on liver ultrasound included increased liver echogenicity and/or nodularity. Statistical analyses were performed to investigate potential relationships between CMR parameters and markers of FALD. Results: Sixty-one patients were included. The median age was 2.7 years at the time of Fontan surgery and 17.0 years at the time of CMR. A larger indexed IVC-CSA was significantly associated with a higher FIB-4 score (Spearman’s ρ = 0.28, P = 0.04), a higher GGT level (Spearman’s ρ = 0.40, P = 0.02), and findings consistent with cirrhosis on liver ultrasound (OR 1.17, 95% CI: (1.01, 1.35), P = 0.04). None of the other measured CMR parameters were associated with markers of FALD. A larger indexed IVC-CSA on CMR was associated with higher systemic ventricle end-diastolic pressure (EDP) on cardiac catheterization (Spearman’s ρ = 0.39, P = 0.018) as well as older age (Spearman’s ρ = 0.46, P = <0.001). Conclusions: A larger indexed IVC-CSA was the only finding on CMR that was associated with markers of FALD. This measure has the potential to serve as an additional non-invasive tool for risk stratification of FALD.