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

BACKGROUND

Dipyridamole stress combined with echocardiography or perfusion scintigraphy can be used to detect coronary artery disease, but head-to-head comparative data are lacking. The aim of this study was to compare the relative 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 previous myocardial infarction, were studied simultaneously using planar perfusion scintigraphy and echocardiography during a high-dose dipyridamole stress, at seven different institutions.

RESULTS

During coronary angiography, 21 patients had non-significant lesions, and 80 had significant lesions (> or = 50% diameter reduction): 37 had single-, 19 double- and 24 triple-vessel disease. Sensitivity 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 echocardiography (coefficient of variation 19.7%) and from 71 to 100% for scintigraphy (coefficient of variation 15%). The angiographically assessed extent and severity of coronary artery disease, evaluated using the Duke score, was correlated to the extent and severity of perfusion defects with scintigraphy (r = 0.65, P < 0.0001) and regional wall motion abnormalities by echocardiography (r = 0.57, P < 0.0001).

CONCLUSIONS

Perfusion scintigraphy and echocardiography have similar accuracies for the non-invasive identification of angiographically assessed coronary artery disease during high-dose dipyridamole stress. Inter-center variability in diagnostic accuracy is higher for echocardiography than scintigraphy. Both methods allow a reasonably accurate estimation of extent and severity of disease, via a semiquantitative assessment of extent and severity of perfusion of functional defects.