The "Super-Fontan" Phenotype: Characterizing Factors Associated With High Physical Performance

Area of Science:

• Cardiology
• Pediatric Cardiology
• Exercise Physiology

Background:

• Fontan circulation typically results in moderately impaired exercise performance.
• A subset of individuals, termed "Super-Fontan," exhibit high physical performance, suggesting a potentially low-risk phenotype.

Purpose of the Study:

• To characterize the "Super-Fontan" phenotype.
• To identify factors associated with normal exercise performance in individuals with Fontan circulation.

Main Methods:

• Utilized cardiopulmonary exercise testing (CPET) to define normal exercise performance (≥80% predicted peak oxygen uptake and work rate).
• Identified "Super-Fontan" and control groups from the Australian and New Zealand Fontan Registry.
• Collected prospective data on physical activity, exercise self-efficacy, and quality of life.

Main Results:

• The "Super-Fontan" group had a lower age at Fontan completion, less frequent dominant right ventricle, and lower obesity rates compared to controls.
• "Super-Fontan" individuals showed less prevalent lung function abnormalities.
• Higher exercise self-efficacy and greater participation in sports and physical activity were observed in the "Super-Fontan" group during development.

Conclusions:

• The "Super-Fontan" phenotype is characterized by healthy weight, earlier Fontan completion, improved exercise self-efficacy, and higher physical activity levels during developmental years.
• This phenotype may represent a favorable, low-risk group within the Fontan population.