Gumm A; Department of Pediatrics, Medical College of Wisconsin, USA.
Ginde S; Hoffman G; Liegl M; Mack C; Simpson P; Vo N; Telega G;
Vitola B; Chugh A

The Fontan procedure results in chronic hepatic congestion and
Fontan-associated liver disease (FALD) characterized by progressive liver
fibrosis and cirrhosis. Exercise is recommended in this population, but
may accelerate the progression of FALD from abrupt elevations in central
venous pressure. The aim of this study was to assess if acute liver injury
occurs after high-intensity exercise in patients with Fontan physiology.
Ten patients were enrolled. Nine had normal systolic ventricular function
and one had an ejection fraction < 40%. During cardiopulmonary exercise
testing, patients had near-infrared spectroscopy (NIRS) to measure oxygen
saturation of multiple organs, including the liver, and underwent pre- and
post-exercise testing with liver elastography, laboratory markers, and
cytokines to assess liver injury. The hepatic and renal NIRS showed a
statistically significant decrease in oxygenation during exercise, and the
hepatic NIRS had the slowest recovery compared to renal, cerebral, and
peripheral muscle NIRS. A clinically significant increase in shear wave
velocity occurred after exercise testing only in the one patient with
systolic dysfunction. There was a statistically significant, albeit
trivial, increase in ALT and GGT after exercise. Fibrogenic cytokines
traditionally associated with FALD did not increase significantly in our
cohort; however, pro-inflammatory cytokines that predispose to
fibrogenesis did significantly rise during exercise. Although patients
with Fontan circulation demonstrated a significant reduction in hepatic
tissue oxygenation based on NIRS saturations during exercise, there was no
clinical evidence of acute increase in liver congestion or acute liver
injury following high-intensity exercise.