EXERCISE ECHOCARDIOGRAPHY VERSUS TI-201 SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY IN EVALUATION OF CORONARY-ARTERY DISEASE - ANALYSIS OF 292 PATIENTS

Background. Exercise echocardiography (digital cine-loop technique) and Tl-201 single-photon emission computed tomography (SPECT) were performed simultaneously in 292 patients being evaluated for coronary artery disease. Methods and Results. Pretreadmill and posttreadmill echocardiographic images of diagnostic quality were obtained in 289 patients, and the left ventricle was divided into anterior, inferior, and lateral regions. Any wall motion or perfusion abnormality observed within each region was classified as totally reversible, fixed, or partially reversible. Exercise echocardiography and SPECT were normal in 137 patients and abnormal in 118 (88% agreement). Equal numbers of regional abnormalities were detected by one test when missed by the other. The two tests had an 82% agreement in detecting the same type of finding within the regions analyzed. SPECT detected more reversible abnormalities than echocardiography, whereas echocardiography detected more fixed abnormalities than SPECT. Regions with a fixed abnormality by echocardiography frequently showed partial reversibility of a perfusion defect by SPECT. Nearly one third of regions with fixed perfusion defects by SPECT demonstrated normal resting function or reversible abnormalities by echocardiography. Sensitivity for coronary artery disease by angiography (greater-than-or-equal-to 50% diameter stenosis) in 112 patients was similar for the two tests, ranging from 58% and 61% (echocardiography and SPECT, respectively) for one-vessel disease to 94% for three-vessel disease. The specificities for echocardiography and SPECT were 88% and 81%, respectively. Conclusions. Exercise echocardiography had a diagnostic accuracy comparable to that of SPECT for the detection of regional abnormalities produced by significant coronary artery disease. A greater number of abnormal regions were detected with the combined use of both tests.