Effect of exercise level on the ability of thallium-201 tomographic imaging in detecting coronary artery disease: Analysis of 461 patients

Abstract

This study examined the effect of the level of exercise on the ability of thallium-201 imaging with single photon emission computed tomography (SPECT) to detect coronary artery disease. Patients in group 1 (n = 164) achieved adequate exercise end points, defined as positive exercise electrocardiograms or greater than or equal to 85% of maximal predicted heart rate. Patients in group 2 (n = 108) had submaximal exercise. The SPECT thallium-201 images showed perfusion defects in 74%, 88%, and 98%, respectively, of patients with one, two and three vessel coronary artery disease in group 1, compared with 52%, 84% and 79%, respectively, of such patients in group 2 (p less than 0.05). Perfusion defects showed partial or complete redistribution consistent with ischemia in 56%, 80% and 88%, respectively, of patients with one, two and three vessel coronary artery disease in group 1 compared with 35%, 58% and 56%, respectively, of such patients in group 2 (p = 0.08, less than 0.03 and less than 0.001, respectively). Of 58 patients with normal coronary angiograms or less than 50% diameter stenosis, 36 (62%) had normal SPECT images. In a separate group of 131 patients with less than 5% pretest probability of coronary artery disease, the specificity was 93%. The sensitivity of exercise SPECT imaging in group 1 was higher than that of ST segment depression (p less than 0.001). Thus, the level of exercise affects the results of SPECT thallium imaging in the localization and evaluation of the extent of coronary artery disease and the detection of ischemia.

Study of the Predictors and Lesion Characteristics of Ischemic Heart Disease Patients With False Negative Results in Stress Myocardial Perfusion Single-Photon Emission Tomography

“…It has been reported that the level of stress has a large impact on the precision of ischemic diagnosis in myocardial scintigraphy. 7 There is a strong possibility that patients who tend to have false negative results did not achieve adequate physiological stress levels during the examination process. In fact, during the examination, symptoms frequently did not appear in patients who had complained of typical angina pain.…”

Non-invasive Evaluation of Internal Thoracic Artery Anastomosed to the Left Anterior Descending Artery with 320-Detector Row Computed Tomography and Adenosine Thallium-201 Myocardial Perfusion Scintigraphy

“…25,26) However, exercise testing is often inadequate and has a negative impact on the sensitivity of scintigraphy for detecting graft disease, because a substantial number of patients referred for imaging cannot exercise or attain maximal heart rates, and many patients continue to use anti-ischemic medications after surgery. [27][28][29] In this study, we performed pharmacologic imaging, which may be advantageous in such patients. No patients with ITA stenosis had regional myocardial ischemia of the LAD territory, as evaluated by adenosine Tl-201-MPS, suggesting that there was no need for re-intervention despite LAD and ITA stenosis.…”

Attenuation of Adenosine-Induced Myocardial Perfusion Heterogeneity by Atenolol and Other Cardioselective β-Adrenoceptor Blockers: A Crossover Myocardial Perfusion Imaging Study

“…By preventing an increase in myocardial oxygen demand, b-blockers attenuate exercise-induced ischemia (1), and this attenuation may result in underestimation of the presence of disease by exercise testing. An advantage of myocardial perfusion imaging (MPI) is that it can be combined with pharmacologic stress agents in patients in whom dynamic exercise may be inadequate (2,3). Until recently, it was thought that b-blockers had no effect on the action of primary coronary vasodilators (1).…”