| [Objective] To investigate the type, nature and composition of plaques by DSCT coronary angiography as a noninvasive means and discuss the accuracy and reliability of diagnosis of coronary artery atherosclerotic plaques in comparison with IVUS. Moreover, evaluate the diagnostic value of analysis of the nature and vulnerability of plaques by DSCT to provide evidence of risk stratification for coronary heart disease events.And through the ABI, baPWV testing, evaluate the diagnostic value of DSCT on risk stages of coronary heart disease.[Materials and Methods] The patients secured diagnosis of coronary heart disease were collected from March 2008 to October 2010 in our hospital and 35 patients who underwent CAG patients performed preoperative DSCT coronary angiography within a month. One or two vessels of all the patients were performed by IVUS examination in the course of surgery. The indicators such as ABI, baPWV of 26 in 35 patients were detected before surgery. The measurement data included vascular lesion area, plaque area, minimum lumen area, local area stenosis, remodeling index, eccentricity index, which were made qualitative and quantitative analysis double-blindly by DSCT and IVUS examinations.The CT values of plaques and above data were measured by DSCT plaque analysis software and plaque calcification was assessed through CACS software.Further, IVUS was used as the reference standard to assess the diagnostic value of coronary atherosclerosis by DSCT, and predict risk stages of coronary heart disease, combined with ABI, baPWV.[Results] 35 patients of 59 vessels (LAD31 branch, LCX13 branch, RCA15 branch),200 coronary segments images can be assessed.1. IVUS showed 9 in 35 cases with coronary artery single-vessel diseases (25.71%),15 with two-vessel diseases (42.86%) and 11 with three-vessel diseases (31.43%), in which 85 plaques distributed in the LAD(53.46%),39 in the RCA(24.53%) and 35 in the LCX(22.01%). 2. For 200 coronary segments, IVUS detected in 159 lesions segments and 41 segments without lesions; while DSCT showed 160 lesions segments, (in which 155 were confirmed by IVUS) and 40 normal segments (in which 36 was confirmed by IVUS).The sensitivity, specificity, positive predictive value and negative predictive value of assessment of coronary atherosclerotic plaque by DSCT were 97%,90%,97%,97%, respectively.3. Compared with IVUS, the detection of mild, moderate, and severe stenosis by DSCT were 81.25%,95.88%,91.30%, respectively. In which for moderate and severe stenosis, the sensitivity was 95%; for the proximal and the middle stenosis, the sensitivity was 92.22% and for the distal stenosis, the sensitivity of was 75.76%.4. Through quantitative analysis of 146 diseases segments in the same segment by DSCT and IVUS, the measurement results such as the vessel area, lumen area, patch area, the stenosis, remodeling index, plaque eccentricity index had non-statistics difference(P>0.05).5. Using IVUS as the reference standard,200 segments were detected.40 in 41 segments (97.56%) were normal; 44 of 63 (69.84%) were lipid plaques; 45 in 50(90%) fibrous plaques and 45 in 46 (97.83%) were calcified plaque, which were secured diagnosed by DSCT. However,30 in 200 segments was incorrectly classified by DSCT. The sensitivities of detection of non-calcified plaque, calcified plaque by DSCT were 81.69%,97.83%, respectively and the specificity were 77.78%,97.83%,respectively.6. Measuring the CT values of all the plaques secured diagnosis by IVUS showed the CT values of lipid plaque was 40±16HU(13～65HU), fibrous plaque 75±20HU(41～132HU)and calcified plaque 435±181HU(134～874HU). The CT values of lipid plaque, fibrous plaque, calcified plaque had significantly different (P<0.05). The CT values of lipid plaque and calcified plaque; fibrous plaque and calcified plaque were both significantly different (P<0.05). While the CT values of lipid plaque and fibrous plaque had no significant difference (P>0.05).7. Coronary artery calcification score increased with the number of diseased vessels, CACS in single-vessel disease was 88.35～235.74; two lesions was 185.72～150.92 and three lesions was 345.47～470.21. CACS increased with the degree of stenosis (r=0.418, P=0.001). However, the degree of calcification and the degree of stenosis was not absolutely consistent. The CACS of 3 in 42 calcified plaque was 1 points, however, the degree of luminal stenosis was moderate. The CACS of 4 plaques were 3 points, but the lumin had no significant stenosis. The CACS of 2 plaques were 4 points, but the lumin showed mild stenosis. The CACS of 1 plaques was 4 points, but there was no significant luminal stenosis.8. The number of lipid plaque, calcified plaque segments in the ACS group and SAP group was statistically significant difference(P<0.05). The eccentricity index and remodeling index between ACS group and SAP group had significant difference (P<0.05). The positive remodeling rates of lipid plaque, fibrous plaque, calcified plaque were 65%,53%,34%, respectively.9. With the increase in the number of disease vessels, ABI decreased, while baPWV gradually increased. ABI and baPWV values in single-branch, two-branch and three-branch were significantly different (P<0.05). Single, two and three lesions ABI and baPWV between the pairwise comparison were statistically significant (P<0.05). The number of detected plaques between ABI <0.9 group and ABI>0.9 had no significant difference (P>0.05,P=0.086), while the stenosis segment was significant difference (P<0.05,P=0.02). The number of detected plaques between baPWV<1400cm/s, baPWV>1400cm/s had significant difference(P<0.05, P=0.001) and the stenosis segment was significant difference (P<0.05, P=0).[Conclusion]1. Each branch of coronary plaque in the distribution of different plaque in the LAD up, LCX least.2.In terms of identifying DSCT coronary plaque with high accuracy.3. DSCT can accurately diagnose coronary artery near the middle of moderate to severe stenosis with high sensitivity.4. In the vascular area, luminal area, plaque area, stenosis, remodeling index, plaque eccentricity index DSCT detection of quantitative indicators are in good agreement with IVUS.5. DSCT can be detected non-calcified plaque and calcified plaque, but non-calcified plaque relatively low sensitivity and specificity.6. DSCT can be based on CT values of the different categories of coronary artery plaque characterization, but the specific distinction between non-calcified plaques there is still insufficient.7. The severity of coronary artery calcification was correlated with, but the degree of plaque calcification correlated with the degree of stenosis is not high.8. Different types of plaques coronary artery vascular remodeling caused by different situation, un-stable plaque vulnerable to positively reconstruction. ACS patients with plaque more, and mostly eccentric plaque distribution, there are multiple lesions of vascular remodeling. When the CT value was some overlap between lipid plaques and fibrous plaques, there was still some value in analysis of plaque vulnerability, combined with eccentric distribution, vascular positive remodeling.9. With the increase in the number of diseased vessels, ABI decreased, while baPWV gradually increased. In ABI<0.9 group and baPWV>1400cm/s group, there were more narrow segments; and in baPWV>1400cm/s group, there were more plaques.ABI and baPWV detection in auxiliary DSCT predict risk of coronary heart disease extent probably some value. |
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