Abstract: ObjectiveTo examine the prognostic value of ^99mT_C-MIBI single-photon emission computed tomography (SPECT) in patients with suspected or diagnosed coronary artery disease (CAD).Methods116 patients with suspected or diagnosed CAD were examined with 99m T_C-MIBI SPECT exercise and rest myocardial imagings, and followed by investigation of cardiac events.Results Follow-up information was complete in 106 patients. Over an average follow-up of 25±8 months, cardiac events occurred in 11 patients. Univariate analyses showed that age, old myocardial infarction, exercise peak heart rate, the change in heart rate from rest to exercise peak, exercise peak systolic blood pressure, the change in systolic blood pressure from rest to exercise peak, abnormal myocardial imaging, the number of myocardial perfusion defect and ischemic volume rate (IVR) were the effective predictors of subsequent cardiac events. Multivariate stepwise Logistic regression analyses revealed that the size of IVR was the only variable with independent predictive value for occurrence of subsequent cardiac events. IVR more than 25% was associated with a significantly increased frequency of subsequent cardiac events (relative risk ratio was 5.9, P<0.005). IVR less than 25% or even normal myocardial perfusion imaging was associated with a very low-risk of cardiac event and a very good prognosis.Conclusion ^99mT_C-MIBI SPECT myocardial imaging is the most effective noninvasive technique that predicted the occurrence of cardiac event in patients with suspected or diagnosed CAD. According to the size of IVR, high-risk and low-risk patients can be effectively identified.

Key words: heart, radionuclide imaging, ^99mT_C, exercise test, coronary artery disease, prognosis, single-photon emission computed tomography