Clinical experience with technetium-99m teboroxime scintigraphy in patients referred for myocardial perfusion evaluation

Abstract

A series of 30 patients (25 males, 5 females, age=28–73 years) with a clinical indication of thallium-201 stress/4 hours redistribution scintigraphy has been studied using stress/rest (n=7) or rest/stress (n=23) protocols with technetium-99 m teboroxime (CARDIOTEC, Squibb Diagnostics) in order to assess the clinical usefulness of this new molecule and to compare it to thallium. In all cases coronary artery disease was known or highly suspected, with a history of myocardial infarction in 18 cases (subacute n=6, remote n=12) and/or previous by-pass surgery or PTC A in 5 cases. Medical treatment was not discontinued at the time of stress testing. Coronary angiography was available for 27 patients.

Exercise tests for both tracers were carried out on an ergometric bicycle during the same day and the levels of exercise achieved for the thallium studies were very similar to those achieved for teboroxime.

Imaging was performed in three planar projections and sudies were evaluated using a model with 4 territories: septal and anterior assumed to correspond to the LAD artery, lateral and latero-posterior (=LCX), inferior and posterior (=RCA) and apex. Classification of results was: normal, ischemic, infarcted and infarcted with ischemia.

With reference to the thallium-201 results, agreement was found in 86% (37/43) of normal regions and in 82% (63/77) of abnormal regions. Relative to documented coronary artery lesions (27 patients) sensitivity and specificity of thallium and teboroxime for exact correspondence between arteries and territories were, respectively: thallium, se=71%, sp=64%, teboroxime, se=67%, sp=75%.

These results indicate the ability of Cardiotec to evaluate myocardial perfusion with an important time saving since the complete study durations (stress and rest) were: thallium=4h 34 min −22 min and teboroxime=1 h 57 min −41 min.