Detecting asymptomatic coronary artery disease using routine exercise testing and exercise thallium scintigraphy in patients with atherosclerotic vascular disease.

ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored exercise testing may enhance sensitivity and specificity of non-invasive evaluation. Thirty-two patients were subjected to ECG-monitored exercise testing, exercise thallium scintigraphy and coronary angiography. The sensitivity of ECG-monitored exercise testing for detecting coronary artery disease was calculated at 81.8% and the specificity at 87.5%, while the figures for exercise thallium scintigraphy were 73.1% and 33.3% respectively. Using these two methods in combination yielded a predictive accuracy of 90.6%. The only advantage of exercise thallium scintigraphy over exercise ECG appears to be in patients in whom the latter test could not be interpreted or was non-diagnostic.