Background Knowledge about how patients with symptomatic aortic stenosis (AS) perform on cardiopulmonary exercise testing (CPET) is sparse. Since exercise testing in patients with symptomatic AS is not advised, submaximal parameters could be of special interest. We aimed to investigate maximal and submaximal physical capacity by CPET before and 1 year after surgical aortic valve replacement (sAVR) in patients with severe AS. Methods In this prospective longitudinal study, 30 adult patients (age 66 +/- 10 years) with severe AS referred for sAVR underwent maximal CPET (respiratory exchange ratio >= 1.05) on a bicycle ergometer before (PRE) and 1 year after (POST) sAVR. Normally distributed data are presented as mean (+/- SD) and non-normally distributed data are presented as median (IQR). Results Median peak workload increased by 8% from 133 (55) watts at PRE to 144 (67) watts at POST (p<0.001). Median ventilatory threshold (VO2@VT) increased from 1216 (391) to 1328 (309) mL/min (p=0.001, n=28). Mean peak oxygen uptake (peakVO(2)) was not significantly different between PRE and POST; 1871 +/- 441 vs 1937 +/- 404 mL/min (p=0.08). The oxygen uptake efficacy slope (OUES) was significantly correlated to PeakVO(2) at both PRE (r=0.889, p<0.05) and POST (r=0.888, p<0.05) Conclusion Physical work capacity was improved 1 year following sAVR, in terms of higher median peak workload and VO2@VT. The strong correlation between the submaximal variable OUES and peakVO(2) suggests that OUES might be a useful surrogate of peakVO(2) in this group of patients where maximal exercise testing is not always recommended.

Aims Exercise testing remains underused in patients with aortic stenosis (AS), partly due to concerns about an exercise-induced drop in systolic blood pressure (SBP). We aimed to study the SBP response to exercise in patients with severe symptomatic AS prior to surgery and 1 year postoperatively. Methods Patients scheduled for aortic valve replacement due to severe symptomatic AS were enrolled at a single centre in a prospective observational cohort study. Maximal cardiopulmonary exercise testing (CPET) was performed on a cycle ergometer at baseline and 1 year postoperatively, using standard termination criteria. The SBP response was categorised according to the last measurements of SBP during exercise, in relation to workload (the SBP/watt-slope) as 'normal' (>0.25 mm Hg/watt), 'flat' (0-0.25 mm Hg/watt) or 'drop' (<0 mm Hg/watt). Results 45 patients (28 male, 66 +/- 9 years, left ventricular ejection fraction 59%+/- 5%, aortic jet velocity 4.6 +/- 0.5 m/s) were included, with pairwise comparison available in 31 cases. There were no adverse events. Preoperatively, 4/45 patients were categorised as 'drop', 23 as 'flat' and 18 as 'normal'. There was a change in the distribution of categories from preoperative to postoperative measurements (43% 'normal' vs 74% 'normal', p=0.0046). Maximal SBP and workload-indexed SBP were higher postoperatively than preoperatively (203 +/- 26 vs 182 +/- 28 mm Hg, p<0.001 and 0.43 +/- 0.14 vs 0.29 +/- 0.15 mm Hg/watt, p<0.001). Conclusion As a drop in SBP was infrequent (<10%) in patients with severe symptomatic AS and no adverse events occurred, our results indicate that CPET may be performed under careful monitoring in AS patients. Postoperatively, the SBP reaction improved, with no patient having a drop in SBP.

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.