Heart disease is the second most common cause of mortality in Taiwan, mainly coronary artery disease (CAD).Quantitative coronary blood flow has been collected by dynamic single-photon emission computed tomography (Dynamic SPECT/CT) for CAD diagnosis in previous studies. However, few studies defined the extent of left ventricle (LV) ischemia on Dynamic SPECT/CT for predicting significant coronary artery stenosis. This study evaluates the extent of LV ischemic blockage in patients suspected of CAD who were referred by cardiologists. A total of 181 patients with suspected CAD were enrolled. They underwent 99mTc-Sestamibi (MIBI) Dynamic SPECT/CT survey before cardiac intervention. Dynamic SPECT/CT has better sensitivity (88%), specificity (96%), and accuracy (94%) compared with those of semi-quantitative MIBI MPI (more than 10%). Results indicated that5% of the LV ischemic extent can yield positive PCI results (>70% stenosis in coronary arteries) compared with the moderate abnormal extent of at least 15% of LV. When the percentage of combined moderate abnormal extent and ischemia extent of LV reaches 27.3%, positive PCI results may be indicated. This study revealed Dynamic SPECT/CT has greater sensitivity, specificity, and accuracy as compared with MPI. Thus, the severity of abnormal perfusion extent of LV on Dynamic SPECT/CT might be beneficial to predict positive PCI results in patients with significant suspicion CAD.
Keywords: CAD; Dynamic SPECT/CT; LV ischemic extent; myocardial perfusion imaging.