High dose dipyridamole myocardial imaging: simultaneous sestamibi scintigraphy and two-dimensional echocardiography in the detection and evaluation of coronary artery disease

Background Dipyridamole stress combined with echocardiography or perfusion scintigraphy can be used to detect coronary artery disease, but head-to-hea d comparative data are lacking. The aim of this study was to compare the re lative accuracy of high-dose dipyridamole stress imaging (up to 0.84 mg/kg over 10 min) with two-dimensional echocardiography and sestamibi perfusion scintigraphy in detecting coronary artery disease, Methods One-hundred and one patients with a history of chest pain and no pr evious myocardial infarction, were studied simultaneously using planar perf usion scintigraphy and echocardiography during a high-dose dipyridamole str ess, at seven different institutions. Results During coronary angiography, 21 patients had non-significant lesion s, and 80 had significant lesions (greater than or equal to 50% diameter re duction): 37 had single-, 19 double- and 24 triple-vessel disease. Sensitiv ity for disease detection was 78% [95% confidence interval (CI) 67-86%] for echocardiography and 79% (CI 68-87%) for scintigraphy. The specificity was 76% (CI 67-84%) for echocardiography and 90% (CI 83-95%) for scintigraphy. The inter-center variation in accuracy ranged from 50 to 100% for echocard iography (coefficient of variation 19.7%) and from 71 to 100% for scintigra phy (coefficient of variation 15%). The angiographically assessed extent an d severity of coronary artery disease, evaluated using the Duke score, was correlated to the extent and severity of perfusion defects with scintigraph y (r = 0.65, P<0.0001) and regional wall motion abnormalities by echocardio graphy (r = 0.57, P<0.0001). Conclusions Perfusion scintigraphy and echocardiography have similar accura cies for the non-invasive identification of angiographically assessed coron ary artery disease during high-dose dipyridamole stress. Inter-center varia bility in diagnostic accuracy is higher for echocardiography than scintigra phy. Both methods allow a reasonably accurate estimation of extent and seve rity of disease, via a semiquantitative assessment of extent and severity o f perfusion or functional defects. Coronary Artery Dis 10:177-184 (C) 1999 Lippincott Williams & Wilkins.