Cardiopulmonary exercise testing for evaluation of a randomized exercise training intervention following aortic valve replacement

Aortic valve surgery is the definitive treatment for aortic stenosis (AS). No specific recommendation is available on how exercise training should be conducted and evaluated after aortic valve replacement (AVR). This study aimed to examine the effect of aerobic exercise training on exercise capacity following AVR. In addition to our primary outcome variable, peak oxygen uptake (peakVO(2)), the effect on submaximal cardiopulmonary variables including oxygen uptake kinetics (tau), oxygen uptake efficiency slope (OUES) and ventilatory efficiency (VE/VCO2 slope) was evaluated. Following AVR due to AS, 12 patients were randomized to either a group receiving 12 weeks of supervised aerobic exercise training (EX) or a control group (CON). Exercise capacity was assessed by a maximal cardiopulmonary exercise test (CPET). There was a significant increase in peak load (+28%, P = 0 center dot 031) and in peakVO(2) (+23%, P = 0 center dot 031) in EX, corresponding to an increase in achieved percentage of predicted peakVO(2) from 88 to 104% (P = 0 center dot 031). For submaximal variables, there were only non-statistically significant trends in improvement between CPETs in EX. In CON, there were no significant differences in any maximal or submaximal variable between CPETs. We conclude that 12 weeks of supervised aerobic exercise training induces significant adaptations in cardiopulmonary function following AVR, especially in regard to maximal variables including peakVO(2). In addition, we provide novel data on the effect on several submaximal variables following exercise training in this group of patients.