Comparative evaluation of bicycle and dobutamine stress echocardiography with perfusion scintigraphy and bicycle electrocardiogram for identification of coronary artery disease

Abstract

In 66 patients with suspected coronary artery disease (CAD), exercise electrocardiography (ECG), exercise echocardiography, dobutamine stress echocardiography (dosage, 5 to 40 μg/kg/min), single-photon emission computed tomography (SPECT) using methoxy-isobutyl-isonitrile (MIBI) and coronary angiography were performed prospectively to compare methods for detecting CAD. CAD was defined as 70% luminal area stenosis in at least 1 coronary artery at coronary angiography. Significant CAD was present in 50 patients. Compared with exercise ECG, exercise echocardiography, dobutamine stress echocardiography and MIBI-SPECT had a significantly higher sensitivity (52% vs 80, 79 and 89%; p < 0.01, p < 0.01 and p < 0.001, respectively). There were no significant differences in sensitivity between exercise echocardiography, dobutamine stress echocardiography and MIBI-SPECT. Specificity of MIBI-SPECT was lowest (71%), whereas exercise ECG, exercise and dobutamine echocardiography had higher specificities (93, 87 and 81%, respectively). Significance, however, was not achieved. Differences in overall accuracy between exercise echocardiography (82%), dobutamine stress echocardiography (80%) and MIBI-SPECT (85%) were not significant. Comparison with accuracy of exercise ECG (62%) was significant (p < 0.05, p < 0.05 and p < 0.01, respectively). In 1-vessel disease, exercise ECG had a lower sensitivity (45%) than exercise and dobutamine echocardiography and MIBI-SPECT (79, 78 and 84%; p < 0.02, p < 0.02 and p < 0.01, respectively). Regarding the 24 patients with false-negative exercise ECG results, 67% had positive exercise echocardiography findings, 71% positive dobutamine echocardiography results and 84% positive technetium-99m MIBI-SPECT results. Thus, exercise echocardiography and dobutamine stress echocardiography are markedly superior in sensitivity to exercise ECG, especially in 1-vessel disease, and represent a useful alternative to myocardial SPECT.