| Background:Coronary heart disease is one of the main death-causing factors of heart diseases. The worldwide incidence of coronary heart disease (CHD) has been on the increase and what is worse, the patients CHD tend to be 5-10 younger in recent years. As a result, early diagnosis of CHD has been one of the much-concerned subjects for both cardiologists and researchers. Pathologic studies have proved that coronary artery calcium (CAC) is one of signs of coronary arteriosclerosis and pathologically, artery arteriosclerosis is the first phase of CHD. Coronary angiography (CAG), which is regarded as the "golden standard" for the diagnosis of CHD and is also often used to follow-up patients after coronary intervention, is somewhat invasive and expensive and requires at least a short hospital stay. Though the application of electron-beam computed tomography (EBCT), a noninvasive and less expensive method compared with CAG, in determining CAC is widely recognized, there have been only a few reports on contrast-enhanced EBCT in the diagnosis of CHD. Our study aims to comparing the results of contrast-enhanced EBCT and those of CAG so as to evaluate the application of contrast-enhanced EBCT, as a substitute of CAG, in the diagnosis of CHD.AIM and Methods:Contrast-enhanced EBCT and CAG were performed in 115 patients with an interval less than 3 months in Xijing Hospital from January 2002 to June 2003, among whom, 83 men and 32 women with a mean age 56 ?8 years (32-76 years). The patients had either been clinically diagnosed as or suspected of CHD. 80 patients had contrast-enhanced EBCT and CAG but without interventional therapy, and 35 patients first had CAG which was immediately followed by interventional therapy, and 6 months after the interventional therapy they had contrast-enhanced EBCT. The results of the contrast-enhanced EBCT were compared with those of CAG angiograms so as to evaluate the application of contrast-enhanced EBCT in the diagnosis of coronary heart diseases.Results:1. Of the 80 patients who had contrast-enhanced EBCT and CAG but without interventional therapy, 17 patients were found to have multivessel disease, 35 single-vessel disease and 28 nonobstructive disease or normal coronaries by CAG. According to the classification of coronary-vessels by CAG, left main coronary arteries (LM), left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX) and right coronary artery (RCA) - 320 vessels from the contrast-enhanced EBCT and CAG were compared. The matching percentages of contrast-enhanced EBCT to the results of CAG were: 75 of 80 (93.8%) of LM, 66 of 80 (82.5%) of RCAs, 62 of 80 (77.5%) of LADs and 49 of 80 (61.3%) of LCXs. Contrast-enhanced EBCT had better coronary imaging of LM and RCA than those of LCX and LAD.2 By anatomical signs, 800 vessels of the proximal, middle and distal parts of LM, LAD, RCA and LCX from the contrast-enhanced EBCT and CAG were compared. The sensitivity of contrast-enhanced EBCT for the identification of coronary artery stenosis (Luminal stenosis >50%) was: LM: 94%; LAD:proximal 90%, middle 68%, distal 43%; RCA: proximal 93%, middle 67%, distal53%; and LCX: proximal 81%, middle 67%, distal 46%. 3. Of the 35 follow-up patients who had received interventional therapy, it was found that in 4 patients the imaging of contrast-enhanced EBCT was too obscure for identification; in the 18 patients with LAD stent, 15 were correctly identified and 3 false-positive, the sensitivity being 83%; in the 10 patients with RCA stent, 8 were correctly identified and 2 false-positive, the sensitivity being 80%; and. in the 7 patients with LCX stent, 5 were correctly identified and 2 false-positive, the sensitivity being 71%.Conclusion:1. The results of contrast-enhanced EBCT are highly correlated with those of CAG. With intravenous contrast enhancement, EBCT can identify the coronary artery and the coronary artery stenosis, especially severe proximal stenosis.2. Contrast-enhanced EBCT is of high value in the follow-up of patients after corona...
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