The value of cardiopulmonary exercise testing in individuals with apparently asymptomatic severe aortic stenosis: A pilot study

Summary Background Risk stratification in asymptomatic patients with severe aortic stenosis (AS) is based on exercise test results. However, differentiating between pathological and physiological breathlessness during exercise is sometimes challenging. Cardiopulmonary exercise testing (CPET) may improve quantification of cardiopulmonary exercise capacity in patients with valve diseases. Aims To assess the ability of CPET to detect abnormal responses to exercise and a clinical endpoint (occurrence of European Society of Cardiology guidelines surgical class I triggers). Methods Forty-three consecutive patients (mean age 69 ± 13 years; 31 men) with no reported symptoms and severe AS (aortic valve surface area  2 or indexed aortic valve surface area ≤ 0.6 cm 2 /m 2 ) prospectively underwent symptom-limited CPET. Results Twelve (28%) patients had an abnormal exercise test (AET) with symptoms (abnormal dyspnoea n  = 11; angina n  = 1). Both VE/VCO 2 slope > 34 (hazard ratio [HR] = 5.76, 95% confidence interval [CI] 1.086–30.587; P  = 0.04) and peak VO 2  ≤ 14 mL/kg/min (HR 6.01, 95% CI 1.153–31.275; P  = 0.03) were independently associated with an AET. Furthermore, VE/VCO 2 slope > 34 (HR 3.681, 95% CI 1.318–10.286; P  = 0.013) and peak VO 2  ≤ 14 mL/kg/min (HR 3.058, 95% CI 1.074–8.713; P  = 0.036) were independent predictors of reaching the clinical endpoint. Conclusions Cardiopulmonary exercise testing is a useful tool for characterizing breathlessness during an exercise test in apparently asymptomatic patients with AS. Peak VO 2  ≤ 14 mL/kg/min and VE/VCO 2 slope > 34 were associated with an AET and the occurrence of European Society of Cardiology guideline surgical class I triggers.