Exercise thallium-201 myocardial scintigraphy in women: Correlation with coronary arteriography

Abstract

Results of exercise thallium-201 myocardial perfusion images, obtained in 60 women suspected of having coronary artery disease, were correlated with coronary angiographic findings. Thirty-two patients had no significant coronary artery disease; 28 patients had severe coronary artery disease defined as 70 percent or greater diameter narrowing of one vessel (14 patients) or multiple vessels (14 patients). The exercise electrocardiogram was positive in 17 patients (9 with and 8 without coronary artery disease), negative in 16 patients (3 with and 13 without coronary artery disease) and inconclusive in 27 patients (16 with and 11 without coronary artery disease). The exercise thallium-201 scintigram showed exercise-induced defects (reversible ischemia) in 21 patients with coronary artery disease, a fixed defect in 1 patient with single vessel disease and previous transmural infarction, but was normal in the remaining 6 patients, who had single vessel disease. The exercise thallium-201 scintigram in subjects with no coronary artery disease was normal in 28, showed an exercise-induced defect in 1 subject and a fixed defect in the remaining 3 subjects. These fixed defects involved the anterolateral segment in the anterior projection and are thought to be due to attenuation of activity by the overlying breasts. Thus, the sensitivity of the exercise electrocardiogram was 32 percent and the specificity 41 percent. In contrast, the sensitivity of exercise thallium-201 scintigraphy was 75 percent and the specificity 97 percent if only exercise-induced defects were considered abnormal and 79 and 88 percent, respectively, if all fixed defects were considered abnormal. It is concluded that exercise thallium scintigraphy is useful in women suspected of having coronary artery disease. Attenuation of activity by breasts may affect the specificity but not the sensitivity. The exercise electrocardiogram is neither sensitive nor specific in this group.