DIAGNOSTIC-VALUE AND INCREMENTAL CONTRIBUTION OF BICYCLE EXERCISE, FIRST-PASS RADIONUCLIDE ANGIOGRAPHY, AND TC-99M-LABELED SESTAMIBI SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY IN THE IDENTIFICATION OF CORONARY-ARTERY DISEASE IN PATIENTS WITHOUT INFARCTION

Background. The diagnostic value and incremental contribution of diffe rent noninvasive tests to the identification of coronary artery diseas e in 128 patients from a general population with intermediate pretest likelihood (48.0%) were determined by ordered logistic regression anal ysis and receiver-operating characteristic (ROC) curves. Methods and R esults. Patients referred for suspicion of coronary heart disease were submitted to bicycle exercise testing under clinical and electrocardi ographic control. At peak exercise, first-pass radionuclide angiograph y was performed after injection of Tc-99m-labeled sestamibi, followed by single-photon emission computed tomographic (SPECT) acquisition, A comparative rest study was obtained within 1 week, and qualitative and quantitative analysis was applied to assess the presence and extent o f disease, With coronary angiography and 50% stenosis used as a standa rd, the discriminative accuracy of each test was calculated, The accur acies to diagnose coronary heart disease were 71.3% +/- 4.7% for the b icycle test, 66.7% +/- 5.3% for radionuclide angiography, and 81.6% +/ - 3.9% for the SPECT data, By ROC curves, the optimal criteria for pos itivity were determined for the visual and quantitative analysis for b oth presence and extent of coronary artery disease, Results of visual and quantitative SPECT were compared in terms of area under the ROC cu rves, The diagnostic performances showed no significant difference, ra nging from 74.3% to 81.6%, The first-pass radionuclide angiographic an d SPECT data were added progressively to the stress testing to evaluat e their incremental diagnostic contribution, Only the addition of SPEC T results significantly increased the accuracy to 85.6% +/- 3.3% (p < 0.0001). Conclusion. Exercise electrocardiography and first-pass radio nuclide angiography showed comparable accuracy to detect coronary arte ry disease, However, the combination of exercise testing and visual SP ECT analytic data sufficed to ensure diagnostic accuracy, without sign ificant benefit from the addition of other tests or the application of quantification.