Head-to-Head Comparison of Peak Upright Bicycle and Post-Treadmill Echocardiography in Detecting Coronary Artery Disease: A Randomized, Single-Blind Crossover Study

Abstract

Post-treadmill digital echocardiography (post-TME) is the most widely used form of exercise echocardiography, but ischemia can rapidly resolve in the postexercise period; peak upright bicycle digital echocardiography (UBE) has the advantage of providing images at peak exercise that reflect normal physiology. However, the comparative accuracy of the two methods in detecting ischemia in the same patients is unknown. To compare the relative diagnostic value of peak UBE and post-TME in detecting coronary artery disease, both tests were performed in 86 consecutive patients undergoing coronary angiography. Eighty-six patients referred for evaluation of coronary disease underwent peak UBE (starting at 25W, with 25-W increments every 3 min) and post-TME (Bruce protocol) in a random sequence. Digitized images of peak UBE and post-TME were interpreted in a random and blinded fashion. More transient wall motion abnormalities were detected with peak UBE than post-TME (55 vs 42, P<.001), and such exercise-induced wall motion abnormalities were more extensive (5.5 ± 3.0 vs 3.4 ± 2.1 dyskinetic segments, P < .001) and more severe (regional wall motion score index, 2.7 ± 0.5 vs 2.5 ± 0.5; P= .003). By angiography, 59 patients had coronary artery disease (a coronary stenosis of ≥50% diameter narrowing); the sensitivity of peak UBE for detecting coronary artery disease was greater than that of post-TME in the population as a whole (88% vs 66%, P < .01) and in the single-vessel subgroup (72% vs 44%, P < .05), with no worsening in specificity (89% vs 89%, P= NS). Peak UBE is more capable of detecting ischemia than post-TME, and this is achieved with no worsening of specificity. Thus, peak UBE should be preferred in patients able to perform bicycle exercise.