The detection of coronary artery disease with radionuclide techniques: a comparison of rest-exercise thallium imaging and ejection fraction response.

Abstract

Patients (52) with suspected coronary artery disease underwent coronary angiography, Tl-201 myocardial imaging and ECG-gated blood pool ventriculography at rest and at maximal exercise. In 11 patients without coronary artery disease, all Tl images were normal. The resting ejection fraction (EF) was normal in all 11 patients and increased during exercise in 6, was unchanged in 3, and decreased in 2. Of the 41 patients with coronary artery disease, the Tl image was normal at rest and exercise in 6 (15%). The exercise EF was abnormal in these 6. A new (18 patients) or enlarged (11 patients) defect appeared on the Tl image in 29 of 41 patients (71%) with coronary disease. Of 41, 6 patients (15%) had an abnormal rest Tl image that was unchanged with exercise. An abnormal rest and/or exercise image defect identified 35 of 41 patients (85%) with coronary artery disease. The resting EF was normal in 26 of the 41 patients (63%) and in 24 patients demonstrated an abnormal response to exercise. Fifteen patients (37%) had an abnormal resting EF, and 14 of these 15 demonstrated persistent abnormalities. An abnormal exercise EF response was identified in 38 of 41 (93%) patients with coronary disease. The specificity of the Tl image was 100% and for the exercise EF determination, 54% (P < 0.02). An abnormal exercise EF response and the rest-exercise Tl image apparently have similar sensitivities for detecting coronary disease; an abnormal exercise ejection fraction was significantly more sensitive than was a new Tl abnormality alone (93% vs. 71%). Combined, the 2 studies detected all patients with coronary disease.