HOW ACCURATE IS DOBUTAMINE STRESS ELECTROCARDIOGRAPHY FOR DETECTION OF CORONARY-ARTERY DISEASE - COMPARISON WITH 2-DIMENSIONAL ECHOCARDIOGRAPHY AND TC-99M METHOXYL ISOBUTYL ISONITRILE (MIBI) PERFUSION SCINTIGRAPHY

Objectives. This study was designed to establish the appropriate diagn ostic criteria for positive dobutamine electrocardiographic (ECG) stre ss test results and to compare their accuracy with those of dobutamine two dimensional echocardiography and perfusion scintigraphy. Backgrou nd. Conventional criteria for positive findings on ECG exercise testin g may not be appropriate for use with dobutamine ECG stress testing. M ethods. One hundred twenty-nine consecutive patients with an interpret able ECG and without previous myocardial infarction were prospectively studied at the time of coronary arteriography. All completed a standa rd dobutamine protocol (5 to 40 mu g/kg body weight per min in 3-min d ose increments) without side effects. Significant coronary artery dise ase, defined as >50% lumen diameter stenosis of a major epicardial cor onary artery on coronary angiography, was present in 83 patients. Empi ric receiver operating curves were generated for various ECG criteria derived from computer-averaged signals. Results. The best ECG criterio n, with a sensitivity of 42% and a specificity of 83%, was an ST segme nt shift, relative to baseline, of 0.5 mm 80 ms after the J point. The sensitivity of this criterion was greater than that of the convention al criterion of 1 mm ST segment depression 60 (23%) or 80 (18%) ms aft er the J point, was comparable to that of chest pain occurring during the test (44%, p = NS) but remained inferior to the sensitivities of t echnetium-99m methoxyl isobutyl isonitrile (mibi) perfusion (76%) or s tress echocardiography (76%, p < 0.001, for both). The specificity of this criterion was not significantly different from that of technetium -99m mibi perfusion tomography (65%) or stress echo cardiography (89%) but was superior to that of chest pain (59%, p < 0.025). Conclusions. We conclude that this new criterion for dobutamine electrocardiograph y is specific but that an imaging technique is still required to accur ately predict coronary artery disease.