Supine Bicycle Echocardiography. Improved Diagnostic Accuracy and Physiologic Assessment of Coronary Artery Disease With the Incorporation of Intermediate Stages of Exercise

Objectives: The purpose of this work was to assess whether the incorporation of intermediate stages during supine bicycle exercise echocardiography (BEE) improves the accuracy of detection of coronary artery disease (CAD) through the evaluation of a biphasic response. Background: Exercise echocardiography allows cardiac imaging throughout exercise. Methods: Exercise echocardiography was performed in 104 patients (mean age 57 ± 11 years, 37 women), 91 of whom underwent coronary angiography. The BEE protocol started at 25 W with increments of 25 W every 3-min stage. Images were digitized at rest, 25 W, 50 W, and peak exercise. Two experienced observers and 1 less experienced observer interpreted rest and peak exercise images, with and without the intermediate stages. Results: Imaging during intermediate stages improved the sensitivity for detection of all individual vessel stenoses (78% vs. 58%, p < 0.001) and patients overall (94% vs. 74%, p = 0.001). The specificity was unchanged (all vessels: 83% vs. 81%, all patients: 64% vs. 60%). A change in left ventricular end-systolic volume from intermediate stage to peak exercise of >10% predicted CAD (sensitivity 94%, specificity 74%) and was more marked than changes observed from rest to peak exercise. The severity of coronary stenosis related to the double product achieved at the onset of ischemia during exercise (r = -0.61, p < 0.001) better than that at maximal exercise (r = -0.31, p < 0.01). Conclusions: During BEE, the acquisition and interpretation of intermediate stages of exercise in addition to peak exercise improves the detection of CAD and allows a better physiologic evaluation of the severity of coronary stenosis.