Aims: Exercise stress testing (EST) is recommended by guidelines to risk-stratify patients with asymptomatic valvular aortic stenosis (AS), though the role of quantitative exercise-Doppler echocardiography has rarely been studied. This prospective study sought to correlate standard EST results with the haemodynamic measurements made during exercise by Doppler echocardiography.
Methods and results: We performed rest and semi-supine exercise Doppler echocardiography in 44 consecutive patients (mean age=68+/-12 years) with aortic valve areas<or=0.6 cm2/m2. The effective aortic valve area (EOA), cardiac output (CO), maximal transvalvular velocity, and pulmonary pressure were monitored over the test. No serious adverse event was observed. EST was positive in 26 (Group 1) and negative in 18 (Group 2) patients. Baseline echocardiographic measurements were similar (EOA 0.77+/-0.15 vs. 0.78+/-0.14 cm2; CO 5.5+/-1.6 vs. 5.9+/-2 L/min) in both groups. Exercise-induced changes in CO (+2.9+/-2 vs. +4.3+/-1.8 L/min, P=0.04) and EOA (-0.04+/-0.18 vs. +0.15+/-0.24 cm2, P=0.015) were significantly greater in Group 2. A correlation between changes in EOA and changes in CO during exercise was observed, but significantly higher in Group 2 (P=0.04).
Conclusion: In the presence of severe asymptomatic AS, exercise Doppler echocardiography, assessing the mechanisms behind a positive EST, appears very promising but further studies with prognosis assessment remain necessary.