Influence of percutaneous pulmonary valve implantation on exercise capacity: Which group of patients benefits most from the intervention?

Background: The aim of the study was to evaluate the role of cardiopulmonary exercise testing (CPET) parameters in assessing exercise capacity improvement after percutaneous pulmonary valve implantation (PPVI). Additionally, it aimed to determine if there are any baseline characteristics influencing that change. Methods and results: The study comprised 32 patients (mean age 26 +/- 9); 53% males; diagnosis: tetralogy of Fallot (n = 18), pulmonary atresia (n = 6), Ross procedure (n = 4), other (transposition of great arteries, pulmonary stenosis, double outlet right ventricle, common arterial trunk type II - n = 4) who underwent successful PPVI due to right ventricular outflow tract dysfunction (predominant pulmonary regurgitation - n = 17, predominant pulmonary stenosis - n = 15). Treadmill CPET was performed before and a year after PPVI along with clinical evaluation, cardiac magnetic resonance and transthoracic echocardiography. Twelve months post successful PPVI (pulmonary valve competence restoration and pulmonary gradient reduction from 58.8 +/- 47.1 to 26.6 +/- 10.8 mm Hg) there was a significant decrease in the ventilatory equivalent for CO2 at peak exercise (EQCO(2)) (25.3 +/- 3.3 to 24.3 +/- 3.0, p = 0.04) and oxygen consumption at peak exercise (pVO(2)) (20.4 +/- 5.0 to 22.6 +/- 5.3 mL//kg/min, p = 0.04). Improved EQCO(2) correlated with an increase in right and left ventricular ejection fraction (respectively R = -0.57, p = 0.002; R = -0.56, p = 0.002). In this study, no baseline factors that might affect improvement in exercise function were found. Conclusions: Successful PPVI leads to an improvement in exercise capacity and hemodynamic response to exercise. The correlation between the improvement in EQCO(2) or peak VO2 and baseline characteristics was too weak to reliably identify the group of patients that will benefit from the procedure.