DETECTION OF CORONARY-ARTERY DISEASE - COMPARISON BETWEEN TECHNETIUM 99M-LABELED SESTAMIBI SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY AND 2-DIMENSIONAL ECHOCARDIOGRAPHY WITH DIPYRIDAMOLE LOW-LEVEL EXERCISE-STRESS

Background Myocardial perfusion imaging in conjunction with dipyridamo le low-level exercise stress has proved its value in the evaluation of patients with coronary artery disease (CAD), Simultaneous wall motion analysis by two-dimensional (2D) echocardiography may provide additio nal information beyond that obtained by myocardial perfusion imaging a lone, The purpose of this study was to compare Tc-99m-labeled sestamib i single-photon emission computed tomography (SPECT) and 2D echocardio graphy for the evaluation of CAD according to a dipyridamole low-level bicycle exercise stress protocol. Methods and Results. We studied 35 consecutive patients referred for the evaluation of chest pain who had undergone coronary arteriography, Tc-99m-labeled sestamibi SPECT and 2D echocardiography agreed in 27 patients (80%) studied for overall de tection of CAD, On a segmental basis, agreement was found between SPEC T and 2D echocardiography in 124 (73%) of 170 segments (Cohen's kappa = 0.43). The accuracy of the combined assessment of myocardial perfusi on and echocardiographic wall motion in detecting CAD was 86%, which w as not different from the accuracy of SPECT alone (80%; difference not significant) but significantly higher than for 2D echocardiography al one (71%; p = 0.03). In the detection of individual coronary artery st enoses, SPECT had a significantly higher accuracy for detecting left a nterior descending coronary artery lesions than had 2D echocardiograph y (80% vs 60%; p < 0.01); combining the two methods did not improve th e accuracy (80%), The combined assessment slightly improved the accura cy for detecting left circumflex coronary artery stenoses from 71% to 83% (p = 0.05). Conclusion. The combined simultaneous assessment of my ocardial perfusion by Tc-99m-labeled sestamibi SPECT and wall motion b y 2D echocardiography did not significantly improve overall accuracy o ver that obtained by Tc-99m-labeled sestamibi SPECT alone. Therefore T c-99m-labeled sestamibi SPECT with dipyridamole low-level exercise str ess appears the preferred imaging modality for the evaluation of patie nts with CAD.