Serial cardiopulmonary exercise testing in patients with previous Fontan surgery

Area of Science:

• Cardiology
• Pediatric Cardiology
• Exercise Physiology

Background:

• Patients with previous Fontan surgery often experience reduced peak oxygen consumption (Vo2), indicating exercise intolerance.
• Limited data exists on the progression of exercise intolerance in this population over time.

Purpose of the Study:

• To assess the longitudinal changes and evolution of exercise tolerance in individuals who have undergone Fontan surgery.

Main Methods:

• Retrospective cohort study of 78 patients with previous Fontan surgery who completed at least two cardiopulmonary exercise tests between 2002 and 2009.
• Analysis of changes in peak Vo2, percent predicted peak Vo2, and associated factors over a mean follow-up of 3.0 years.

Main Results:

• Peak Vo2 decreased from 63.7% to 60.4% predicted over the study period.
• A significant decline in percent predicted peak Vo2 was observed at a mean rate of 1.25 percentage points/year (p < 0.001).
• The rate of decline was more pronounced in patients under 18 years old (1.78 percentage points/year) and less marked in adults (0.54 percentage points/year).

Conclusions:

• Exercise function in Fontan survivors tends to decline during late adolescence.
• Exercise tolerance appears to stabilize in early adulthood for patients with previous Fontan surgery.
• Ventricular morphology, Fontan procedure type, and medications did not predict progressive exercise intolerance.