789 Cardiopulmonary exercise testing in repaired tetralogy of Fallot patients: correlation with the level of physical activity and cardiac magnetic resonance imaging

Abstract

Abstract Aims Patients with repaired Tetralogy of Fallot (rToF) tend to have a decent life free of limitations. In asymptomatic individuals, cardiac magnetic resonance imaging (MRI) is used to determine if pulmonary valve replacement (PVR) is necessary. Cardiopulmonary exercise testing (CPET) could aid in determining the extent of functional impairment. Methods and results rToF patients who had an MRI and CPET between 2019 and 2021 in a brief interval (<1 year) were included in the study. Data were gathered on demographics, CPET parameters, MRI, type of surgery, clinical functional class, QRS duration, arrhythmic events, and level of physical activity. A total of 83 participants were enrolled in this study. There was a slight decrease in exercise capacity (median peak VO2/kg 30; range 25–33 mlO2/kg/min). Peak VO2 (r = 0.28), peak VO2/kg (r = 0.40), VO2 at AT (r = 0.31), peak oxygen pulse (r = 0.26), and oxygen uptake efficiency slope (OUES) (r = 0.35) values were found to have a positive association with right ventricular (RV) size. No significant correlation was observed between CPET parameters and PR, LVEF, and RVEF. A significant positive association was detected between right ventricular end-diastolic volume index (RVEDVi) and exercise capacity, especially up to 160 ml/m2. The analysis of the International Physical Activity Questionnaire (IPAQ) replies revealed a statistically significant relationship between the level of physical activity and both peak HR and the indexes of ventilatory efficiency. Conclusion In rToF patients with moderate–severe PR, NYHA class I, preserved RVEF, a slight reduction in exercise tolerance was detected. OUES could also be valuable to this population. A positive association was found between RV dilation and exercise performance up to 160 ml/m2 of RVEDVi, suggesting that perhaps at this cut-off value of RVEDVi, PVR could start being considered.