Abdominal skeletal muscle index as a potential novel biomarker in adult Fontan patients

Abstract Background Fontan palliation results in a chronic multisystem disorder with diminished exercise capacity and increased risk of muscle wasting. The aims of this study were to assess feasibility of skeletal muscle mass measurements in Fontan patients undergoing MRI liver surveillance, to compare muscle mass with a historic control and to assess its correlation with cardiorespiratory fitness. Methods Skeletal muscle area (SMA) and skeletal muscle area index (SMI) were measured at T12 and L3. A young, healthy historic cohort was used as a comparison group. Results Forty patients with a Fontan circulation (mean age 25.5±7.9 years, 50% men) were included. Measurements of SMA and SMI were feasible and highly reproducible. Mean SMA and SMI were significantly lower in women compared with men, both at T12 (SMA: 25.1±4.9 versus 33.5±8.4cm2, p Conclusions Abdominal skeletal muscle mass can be reproducibly determined on surveillance liver MRIs. Muscle wasting appears to occur commonly in Fontan patients. Further research is needed to better define the value of SMI as a biomarker in the Fontan population.