Most single ventricle patients undergo Fontan procedure in a staged manner. However, optimal timing of Fontan completion after an intermediate staging surgery is controversial. Therefore, we investigated the long-term impact of age at Fontan completion on the exercise performance in adolescents.

We analyzed National Institutes of Health/National Heart, Lung and Blood Institute Pediatric Heart Network Fontan Cross-Sectional Study dataset consisting of children and adolescents 6 to 18 years of age recruited in 2003 to 2004. Multivariate linear regression techniques were used to evaluate association of age at Fontan procedure with percent predicted VO₂ maximum, percent predicted maximum O₂ pulse, and heart rate reserve in patients who achieved ventilatory anaerobic threshold (VAT).

Of the 405 patients who had undergone only one Fontan operation and ramp cycle ergometry, 72% had prior intermediate surgery. Mean age at Fontan completion and exercise testing was 3.4±2 and 12.4±3.2 years. Three hundred twelve patients reached VAT suggesting adequate cardiopulmonary effort. In patients who reached VAT, each year increase in age at Fontan completion was associated with a decline of 1.5 (95% CI −2.5 to −0.5) points in percent-predicted VO₂ maximum and a decline of 4.1 (95% CI −6.0 to −2.1) beat/min in heart rate reserve after adjusting for all pertinent variables.

Fontan completion at a younger age is associated with better exercise performance in adolescents.