A Study Of Plaque Characteristics And Risk Of Coronary Arteriosclerosis On MSCT

Objective: The purpose of this study was to evaluate the diagnostic accuracy of 64-slice coronary computed tomographic angiography in coronary artery disease,and to test the value and limit of three types of coronary atherosclerotic plaque in detecting coronary stenosis. To analysis the relationship between coronary atherosclerosis and coronary artery stenosis. To use m-ultislice computed tomographic (MSCT) coronary angiography to compare the prevalence, extent, and composition of coronary atherosclerotic lesions between Uygur and Han ethnic groups in Xinjiang with suspected coronary artery disease (CAD). To analyze the risk factors for present of coronary atherosclerotic plaques detected by MSCT in Uygur and Han ethnic groups in Xinjiang with suspected CAD. Noninvasive determination of plaque burdenmAy be important for improving coronary risk stratification. Methods: 1) Eight patients with suspected coronary artery disease underwent 64-slice CT coronary angiography and invasive coronary angiography (ICA) were included in the study. The sensitivity, specificity, positive predictive value, and negative predictive value of MSCT were determined with ICA as standard of reference. Coronary artery plaques were classified as calcified, non-calcified and mixed plaques based on MSCT, and coronary stenosis were detected by both MSCT and ICA. Stenosis of coronary segments classified as normal, mild, moderate and severe degree based on ICA. The relationship between different coronary lesions and stenosis degree of coronary segments were determined. 2) Totally 1272 cases (912 Han cases with mean age of 56.60±11.16 years old and 360 Uygur cases with mean age 52.62±10.50 years old) with suspected CAD who underwent 64-Slice CT coronary angiography were included consecutively from Jan 2008 to Dec 2010. Each coronary artery segment was evaluated respectively for presence of atherosclerotic plaque, plaque types (calcified, noncalcified, or mixed), plaque location, stenosis of coronary artery segment. Coronary artery calcium score was compared between the groups using multivariate linear regression analysis. 3) In this cross-sectional study, we included consecutive Uygur and Han subjects who presented with suspected CAD. Contrast- enhanced 64-slice coronary MSCT was performed to determine the presence of coronary atherosclerotic plaques for each person. Traditional risk factors of CAD (height, weight, systolic blood pressure(SBP), diastolic blood pressure(SBP), fasting blood-glucose (FBG), smoking history, family history, triglyceride (TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol(LDL-C))were collected. Logistic regression analysis was used to reveal risk factors for coronary atherosclerosis plaque formation. Results: 1) 98.75%patients,96.88%coronary branches and 97.25%coronary segments were depicted with a diagnostic image quality, respectively. The patient-based sensitivity, specificity, PPV (Positive predictive value), and NPV (Negative predictive value) for the diagnosis of≥50%coronary artery stenosis were 97.92%、90.32%、94.00%、96.55%, respectively. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of≥50%coronary artery stenosis were 92.13%、95.93%、90.11%、96.80%, respectively. The segment-based sensitivity, specificity, PPV, and NPV for the diagnosis of≥50%coronary artery stenosis were 90.74%、98.87%、89.09%、99.05%, respectively. For calcified plaques, non-calcified plaques and mixed plaques, the AUC ROC for identification of segments with≥50%coronary artery stenosis by MSCT was 0.865, 0959 and 0.980, respectively. For calcified plaques, quantitative coronary stenosis analysis revealed a moderate correlation (r=0.72) and agreement between MSCT and ICA. For non-calcified and mixed plaques, quantitative coronary stenosis analysis revealed a good correlation (r=0.895; r=0.895) and agreement between MSCT and ICA. There was a significant relationship between plaque composition and stenosis severity. At greater levels of stenosis severity, mixed plaques were most common and calcified plaques were less common, while at milder levels of stenosis severity. 2) The detection rate of coronary atherosclerosis plaque in total sample was 56.92%. There was no significant difference between Uygur and Han ethnic groups with respect to total detection rate of plaque(χ~2=0.410,P=0.522). The detection rate of Uighur men in 40-year-old age group is higher than the Han men (χ~2=3.916, P=0.048), and the detection rate of Uighur women in the 50-year-old age group is higher than the Han women (χ~2=11.481, P=0.001). The atherosclerotic plaque types differed between Uygur and Han ethnic groups, with relatively more noncalcified disease in Uygur individuals and more calcified disease in Han individuals(χ~2=37.583,P=0.000). ThemAin branch of coronary artery involved by calcium is left anterior descending artery (LAD), followed by right coronary artery (RCA), left circumflex branch (LCX) and leftmAin coronary artery (LMA). No statistical difference was found in the location of calcification between Uygur and Han cases (χ2=10.188,P=0.017). Comparison with Han ethnic group, degree of coronary segment stenosis caused by plaque was more sever in Uygur ethnic group (Z=-2.588, P=0.010). There were no significant differences in coronary artery calcium score of total arteries, LAD, RCA , LCX and LMA in Uygur and Han ethnic groups (total calcium score:Z=-1.214, P>0.05; calcium score of LMA: Z=-1.057, P>0.05; calcium score of LAD: Z=-0.770, P>0.05; calcium score of LCX: Z=-0.863, P>0.05; calcium score of RCA: Z=-0.918, P>0.05). Multiple linear regression results showed age and gender were associated with calcium score of total arteries, LAD, RCA, LCX and LMA , but ethnic showed no correlated with coronary artery calcium score. Total coronary artery calcium score increases with age, and the total coronary artery calcium score of the women was higher than that of the men in the same age group. 3) A total of 724 (56.92%) subjects had coronary atherosclerotic plaque while 548 (43.08%) had no identifiable plaques. Logistic regression analysis demonstrated that Uygur ethnic group, increased age,history of smoking, history of family CAD and increased SBP were the risk factors for the presence of coronary plaque (Uygur ethnic group: OR 1.427; 95%CI 1.064-1.915; age: OR 1.086; 95%CI 1.068-1.100; history of smoking: OR 1.701; 95%CI 1.518-1.958; history of family CAD: OR 1.699; 95%CI 1.135-2.484; increased SBP: 1.007; 95%CI1.004-1.016), while female gender and increased HDL-C were protective factors for the presence of coronary plaque (female gender: OR 0.430; 95%CI 0.309-0.594; increased HDL-C: OR 0.627; 95%CI 0.439-0.894). For Han ethnic group, Logistic regression analysis demonstrated that increased age,history of smoking, increased TG and increased SBP were the risk factors for the presence of coronary plaque (age: OR 1.090; 95%CI 1.069-1.112; history of smoking: OR 1.376; 95%CI 1.252-1.561; increased SBP: 1.016; 95%CI1.009-1.023; increased TG: 1.232; 95%CI1.058-1.435), while female gender and increased HDL-C were protective factors for the presence of coronary plaque (female gender: OR 0.337; 95%CI 0.225-0.505; increased HDL-C: OR 0.583; 95%CI 0.355-0.960). For Uygur ethnic group, Logistic regression analysis demonstrated that increased age,history of smoking, history of family CAD and increased LDL-C were the risk factors for the presence of coronary plaque (age: OR 1.074; 95%CI 1.047-1.102; history of smoking: OR 2.037; 95%CI 1.167-3.554; history of family CAD: OR 2.256; 95%CI 1.108-4.592; increased LDL-C: 1.548; 95%CI1.641-3.734), while increased HDL-C were protective factors for the presence of coronary plaque (increased HDL-C: OR 0.387; 95%CI 0.153-0.983). Conclusion: 1) MSCT is a noninvasive tool that allows accurate evaluation of coronary artery stenosis. For non-calcified and mixed plaques, quantitative coronary stenosis analysis revealed a good correlation and agreement between MSCT and ICA. Mixed plaques were most common at greater levels of stenosis severity. that an initial unenhanced scan to evaluate for the presence of extensive calcium could avoid suboptimal coronary CTA in patients with severe calcifications. 2) Characteristics of coronary atherosclerotic plaque can be detected noninvasively by MSCT. Study results suggest that atherosclerotic plaque burden and composition, as measured by using coronary CT angiography, differ between Uygur and Han ethnic groups with suspected CAD. 3) Our data suggest that Uygur ethnic group was the risk factors for the presence of coronary plaque. Logistic regression analysis results revealed risk factors for coronary atherosclerosis plaque formation were not exactly the same between Uygur and Han ethnic groups in Xinjiang with suspected CAD.