Persistent Thallium-201 Stress-Redistribution Defect: Can Artériographie or Other Clinical Variables Predict Late Redistribution?

Abstract

The ability of artériographie, electrocardiographic, and physiologic indices of exercise testing to predict the reversibility of the persistent defect visualized on poststress and early (2-4 h) thallium-201 redistribution imaging was assessed in 35 consecutive patients who had arteriography within 6 months of their scintigraphic study. Postexercise, early, and late (24-72 h) redistribution images were scored on a scale of 0-3. Moderate to complete late redistribution (scores 2 and 3) was found in 23 (66%) patients (group I). Of these patients in group I, 19 had no significant early redistribution (group IA). There was little or no late redistribution (0-1) in 12 patients (group II). Late redistribution of thallium-201 in persistent myocardial defects was prevalent in the culprit vascular distribution in patients with Q wave myocardial infarction, but was more prevalent in patients without the presence of Q waves on the electrocardiogram. No difference was found between groups I and II, respectively, in exercise time, angina pectoris on exertion, rate-pressure product, ischemic electrocardiographic changes, and number of coronary vessels with > 50% luminal narrowing. The degree of stenosis of the culprit artery did not correlate with the presence of late redistribution. Except for a trend in group IA patients to have more frequent angina pectoris on exertion, similar results were obtained comparing group IA with group II. We conclude that neither symptomatic, hemodynamic, and electrocardiographic variables of standard treadmill testing nor the degree of stenosis of the culprit coronary artery by coronary cineangiography can distinguish patients who manifest evidence of ischemia and viability by late-redistribution imaging of persistent myocardial defects following single-dose administration of thallium- 201.