SIMULTANEOUS DOBUTAMINE STRESS ECHOCARDIOGRAPHY AND TC-99M ISONITRILESINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY IN PATIENTS WITH SUSPECTEDCORONARY-ARTERY DISEASE

Objectives. The purpose of this study was to determine the relative va lue of dobutamine stress echocardiography and technetium-99m isonitril e single-photon emission computed tomography (mibi SPECT) in the detec tion of myocardial ischemia. Background. Stress-induced new wall motio n abnormalities and transient perfusion defects are both used for the diagnosis of myocardial ischemia. Methods. One hundred five consecutiv e patients with either proved or suspected coronary artery disease, wh o were referred for perfusion scintigraphy, were studied by a combinat ion of the two techniques. Both echocardiographic and mibi SPECT image s were visually analyzed. Three patients were excluded from the final analysis because of unsatisfactory examinations: two with noninterpret able stress echocardiograms and one with noninterpretable mibi SPECT i mages. The response to stress was concordantly classified by both tech niques in 68% of patients (kappa 0.51). Results. Dobutamine stress ech ocardiography revealed the presence of ischemia in 38 and mibi SPECT i n 45 patients (overall agreement = 74%, kappa = 0.46). The agreement w as higher in patients without previous myocardial infarction (84%, kap pa = 0.62). When regional analysis was performed, concordance of stres s echocardiography and mibi SPECT occurred in 84% of the 306 regions ( kappa = 0.45). Regional agreement was also slightly higher in patients without previous infarction (88%, kappa = 0.50). In 21 patients witho ut previous myocardial infarction who underwent coronary angiography, the overall sensitivity of dobutamine stress echocardiography and mibi SPECT for the diagnosis of coronary artery disease (diameter stenosis >50%) was 75% and 83 %, respectively, with a specificity of 89 % (eig ht of nine patients) for both tests. Conclusions. Dobutamine stress ec hocardiography represents a reasonable alternative to dobutamine mibi SPECT for the functional assessment of patients with suspected myocard ial ischemia and without previous myocardial infarction.