Relation of Liver Volume to Adverse Cardiovascular Events in Adolescents and Adults With Fontan Circulation.

Elevated central venous pressure in those with Fontan circulation causes liver congestion and hepatomegaly. We assessed if liver volume by magnetic resonance imaging (MRI) is associated with adverse cardiovascular outcomes. Retrospective study of 122 patients with Fontan circulation who were >10 years old and had a liver MRI with magnetic resonance elastography. Liver volume (ml) was measured by manual segmentation from axial T2-weighted images and was indexed to body surface area. The composite outcome included death, heart transplant, ventricular assist device placement, or nonelective cardiovascular hospitalization. The median age at the time of MRI was 18.9 (interquartile range 15.8 to 25.9) years, and 47% of the patients were women. The mean indexed liver volume was 1,133 ± 180 ml/m. Indexed liver volume was not significantly associated with age, years since Fontan, or with liver stiffness (r = 0.15, p = 0.10), but was positively correlated with Fontan pressure (r = 0.32, p = 0.002). Over a median follow-up of 2.1 (0.8 to 4.2) years, 32 patients (26%) experienced the composite outcome. Higher indexed liver volume was associated with a greater hazard for the composite outcome (hazard ratio per 1 SD increase = 1.74, 95% confidence interval 1.27 to 2.35, p = 0.0004) but increased liver stiffness was not significantly associated with the composite outcome (hazard ratio per 1 SD increase 1.44, 95% confidence interval 0.90 to 2.21, p = 0.11). In conclusion, greater liver volume indexed to body surface area is associated with unfavorable hemodynamics and adverse outcomes in patients with Fontan circulation. Liver volume may be a useful, simple imaging biomarker in adolescents and adults with Fontan circulation.