Short-Term Change of Exercise Capacity in Patients with Pulmonary Valve Replacement after Tetralogy of Fallot Repair

BACKGROUND AND OBJECTIVES The aim of this study was to investigate the effect of pulmonary valve replacement (PVR) on exercise capacity and determine cardiopulmonary exercise (CPEX) parameters associated with improvement in right ventricle (RV) function. SUBJECTS AND METHODS We retrospectively analyzed CPEX and magnetic resonance imaging parameters in a total of 245 patients who underwent PVR from January 1998 to October 2015. In addition, we analyzed the characteristics of the patients who showed improved exercise capacity after PVR. RESULTS Twenty-eight patients met the inclusion criteria for the study. CPEX parameters after PVR showed no significant changes in all patients. However, baseline predicted peak oxygen uptake (VO2peak) (%) value was significantly lower in patients with significant improvement in exercise capacity after PVR, as compared to patients who showed decreased exercise capacity after PVR (60.83±10.28 vs. 75.81±13.83) (p=0.003). In addition, patients with improved exercise capacity showed a positive correlation between the change of right ventricular ejection fraction (RVEF) (%) and the change of anaerobic threshold (r=0.733, p=0.007); whereas, patients with decreased exercise capacity showed a negative correlation between the change of RVEF (%) and the change of predicted VO2peak (%) (r=-0.575, p=0.020). CONCLUSION The importance of predicted VO2peak (%) in evaluating exercise capacity differentiated from other CPEX variables. The change of anaerobic threshold and predicted VO2peak (%) might be a useful predictor of the change in RV function after PVR.