COMPARISON BETWEEN DOBUTAMINE ECHOCARDIOGRAPHY AND TL-201 SCINTIGRAPHY IN DETECTING RESIDUAL STENOSIS, ISCHEMIA, AND NECROSIS IN PATIENTS WITH PRIOR MYOCARDIAL-INFARCTION

Background: Following the first attempts to detect myocardial ischemia with two-dimensional echocardiography stress testing, pharmacologic s tress using dobutamine infusion has become an alternative to echocardi ography exercise testing for evaluation of coronary artery disease. It has been shown that stress echocardiography has a diagnostic accuracy similar to that of an exercise thallium test. Other studies, however, indicated that radionuclide myocardial per-fusion imaging was more se nsitive than exercise or pharmacologic stress echocardiography for det ection of ischemia or jeopardized myocardium. Hypothesis. The aim of t he present study was to determine the ability of dobutamine stress ech ocardiography in comparison with thallium-201 scintigraphy to identify multivessel disease and the presence of myocardial scar and ischemia in 60 consecutive patients who suffered a first myocardial infarction (MI). Methods: Patients were evaluated by coronary angiography and ven triculography, thallium-201 (Tl-201) tomographic scintigraphy, and dob utamine echocardiography within 3 months of a first MI. Forty-seven ha d Q-wave MI and 13 had non-Q-wave MI, Eleven patients were excluded fr om final analysis-7 because of failure to achieve target heart rate in spite of the use of atropine, and 4 because of high blood pressure fo llowing the infusion of dobutamine. Results: Dobutamine echocardiograp hy showed an overall sensitivity of 43% for detection of coronary arte ry lesions of 50-74% diameter stenosis and Tl-201 scintigraphy showed a sensitivity of 71%. For detection of lesions of greater than or equa l to 75% diameter stenosis, dobutamine echocardiography showed a sensi tivity of 52% and Tl-201 a sensitivity of 70%. Overall agreement betwe en wall motion and myocardial perfusion for detection of necrosis and/ or ischemia in the infarct area was 40.4% with a kappa coefficient of 0.09 (p = 0.13). For detection of ischemic myocardium outside the infa rct zone, overall agreement was 78.6% with a kappa coefficient of 0.49 (p < 0.0001). Conclusion: Dobutamine echocardiography results showed a lower sensitivity than myocardial perfusion images in predicting mul tivessel coronary artery disease, and there was poor agreement between both methods in identifying necrosis or ischemia.