Exercise oscillatory ventilation in patients with Fontan physiology.

Area of Science:

• Cardiology
• Pulmonary Medicine
• Pediatric Cardiology

Background:

• Exercise oscillatory ventilation (EOV) involves regular oscillations in minute ventilation during exercise.
• EOV presence correlates with heart failure severity and poorer prognosis in adults.
• Its role in single ventricle Fontan physiology was previously unevaluated.

Purpose of the Study:

• To evaluate the prevalence of EOV in patients with single ventricle Fontan physiology.
• To determine the predictive value of EOV for adverse outcomes in this population.

Main Methods:

• Cross-sectional and prospective survival analysis of 253 patients post-Fontan procedure.
• Cardiopulmonary exercise testing (CPET) data analyzed for EOV presence and clinical outcomes.
• EOV defined as regular oscillations >60% of exercise duration with amplitude >15% of average VE.
• Cox regression used for survival analysis, assessing mortality, heart transplant, and hospitalization.

Main Results:

• EOV was present in 37.5% of the 253 subjects.
• EOV associated with younger age, higher NYHA class, and increased VE/VCO2 slope.
• EOV predicted increased risk of death or heart transplant (HR, 3.9; P=0.002).
• EOV predicted combined adverse outcomes (death, transplant, or hospitalization) after multivariable adjustment (aHR, 2.0; P=0.01).

Conclusions:

• Exercise oscillatory ventilation is prevalent in the Fontan population.
• EOV is a strong predictor of reduced transplant-free survival in Fontan patients.