Sports practice predicts better functional capacity in children and adults with Fontan circulation

Peak oxygen uptake (peak VO₂) and its decline predict death or serious cardiovascular adverse events in patients with Fontan circulation. Our aim was to study VO₂ in a population of Fontan patients with variable age and contemporary surgical correction, and find predictors of functional status which could lead to management changes.

Prospective cardiopulmonary exercise test was performed on a treadmill. Blood tests and transthoracic echocardiogram were performed on the same day. Dependent variables were defined as: VO₂ at ventilatory threshold (VT) as a percentage of the predicted peak VO₂ and peak VO₂ as a percentage of its predicted value. Statistical analysis was performed on SPSS® version 23 and significance was defined as a p-value < 0.05.

Forty-eight patients were included for analysis. All had a lateral or extracardiac conduit. Mean age was 18.2 years (SD 6.2). Mean age at Fontan completion of 6.5 years (SD 2.3) showed no association with functional capacity. Mean percent VO₂ at VT was 37.6% (SD 9.4) and percent peak VO₂ was 67.8% (SD 16.7). VO₂ both at ventilatory threshold and peak was associated with age, weekly sports practice, significant atrioventricular regurgitation and having a pacemaker or being on antiarrhythmic drugs. On multivariate analysis, weekly sports practice was the best predictor for VO₂ values.

Sports practice is a modifiable factor that significantly impacts functional capacity in Fontan patients despite their age. Clinicians should actively prescribe and promote physical activity in this population, either with regular sports practice or engagement in cardiac rehabilitation programs.