RELATIVE ROLE OF CORONARY STENOSIS SEVERITY AND MORPHOLOGY IN DETERMINING PHARMACOLOGICAL STRESS ECHO POSITIVITY

Angiographically assessed plaque morphology, not only plaque severity, may affect myocardial vulnerability to ischemia during stress testing . The aim of this study was to evaluate directly, in a head-to-head co mparison, the relation between coronary stenosis severity and morpholo gy and pharmacologic stress echo response. From our inpatients echo da tabank, we selected 68 patients (62 men, mean age 57 +/- 9 years) who had undergone high-dose dipyridamole and high-dose dobutamine-atropine echocardiography, performed within 1 week and in random order, before coronary angiography that showed significant coronary artery disease by selection. There were altogether 121 vessels with visually assessed stenosis > 50% in 68 patients. Thirty-three had complex-type and 56 s imple-type lesions (according to the Ambrose classification), whereas 32 vessels were occluded. During dobutamine echocardiography there wer e 51 dyssynergic regions of the left ventricle fed by different corona ry arteries in 50 patients and dipyridamole stress was able to induce ischemia in 45 separate regions in 44 patients. The overall agreement between the 2 tests in recognizing ischemia was 76%. induced ischemia was associated with greater quantitatively assessed stenosis severity for both dipyridamole (positive, 70 +/- 12% vs negative, 63 +/- 12% ar ea reduction; p <0.05) and dobutamine (positive, 68 +/- 12% vs negativ e, 63 +/- 12% area reduction; p <0.05). The simple-type stenosis was m ore frequently identified with dobutamine (46%) versus dipyridamole (2 1%, [p <0.01]), whereas the complex-type stenosis was associated with a trend toward more frequent positivity of dipyridamole (55%) versus d obutamine (36%), p = 0.13. Adenosinergic stress positivity is affected not only by plaque severity, but also by plaque morphology, whereas a drenergic stress positivity is affected by plaque severity, not by pla que morphology. (C) 1998 by Excerpta Medico, Inc.