Cta Research On Coronary Artery Remodelling And Plaque Trait Of Dyslipidemia Patients

Purpose:By using technique of 64slice spiral CT coronary artery imaging, the author analyzes Coronary Artery Remodelling and Atherosclerosis of Dyslipidemia Patients, then discusses interventional point and focuses of primary prevention for Dyslipidemia Patients' coronary heart disease, and finally discusses its role in secondary prevention of coronary heart disease.Materials and methods:1. data collection From May 2009 to October 2011, The author collected 123 cases in which dyslipidemia patients have coronary CTA examinations in our hospital, recorded specific parameters of blood lipids for patients, whether the patients have hypertension or hyperglycemia, their age, gender, smoking status, whether there is anyone who has vascular disease in the family history and asked in detail about medical history of angina pectoris or myocardial infarction. From the investigation, I get the following information: there are 20 patients with stable angina pectoris in 123 cases,16 patients have acute coronary syndrome,87 patients have atypical angina symptoms. According to dyslipidemia risk stratification schemes in the prevention guidelines of Chinese adult dyslipidemia,87 cases in which patients have asymptomatic symptoms can be divided into high risk, medium risk, low risk 3 groups. Exclusion criteria:patients who have operation of coronary artery stent placement, patients with no dyslipidemia but with acute heart failure; Tachycardia (can not be controlled or after control, it is still more than 75bpm), severe arrhythmia; severely allergic to iodine contrast agents; severe renal insufficiency.2. Main equipment:A, Using American GE64 Lightspeed VCT-XT spiral CT scanner. B:Reconstructing workstations:GE AW4.4 workstation for post-processing.3. Scanning scheme:With the patient in the supine position, the entire scanning includes plain CT scan, test bolus and CTA scanning. All patients'plain CT scan will use non-enhanced ECG gating scan. All patients' Test bolus scan uses axial scan mode, Is rotation time,5mm detector coverage. ROI is placed in Opening level of the ascending aorta and left coronary artery, time to obtain the level-density curves to determine scan time of the coronary angiography. The CTA of coronary artery:a,65bmp＜heart rate <70bmp, patients should have retrospective ECG gating scan, using the following parameters:usage amount of contrast agent=0.8ml/kg×patients' weight kg, injection speed of contrast agent= dosage of contrast agent ml/13S, and an additional 40ml saline, scanning area:15mm more than the highest point of the left coronary artery in the plain CT scan to the scope of the diaphragm; when using axial scan mode, optional pitch of the machine is appropriate for heart rate 30～70 bpm.40mm detector coverage, spiral width 0.625mm (total exposure time about 5-8s),120kV,621mA. b, patients with heart rate less than 65bmp, Test bolus and its previous scan was the same with a, so is contrast agent injection parameters and scan range.4. Based on the scan data of Data reconstruction and reorganization of processing the original image reconstruction, we can get the corresponding R-R interphase, the best pictures come from multi-temporal data interval 3-5% R-R interval reconstruction, Thick layer of reconstruction 0.625mm, which is single-sector reconstruction. Cardiac IQ post-processing software which is used to evaluate coronary artery, mainly use EDIT SECTION to measure the highest risk of plaque LA, VA, RLA, RRA, the maximum diameter of plaques and minimum radical line. Reference position refers to normal position of lesion proximal or distal end. In bifurcation lesions, distal end is used as reference position to observe whether the coronary arteries have any plaques, to evaluate plaque vulnerability and give a mark, to record all plaques segments and tell each patient where the highest risk of plaque segment is. And at last work out RI,PB,EI and SR. Using Schroeder coronary CTA and Autopsy pathology results as criteria, plaques can be divided into soft plaques, middle plaques and calcified plaques according to the CT number.Risk ranking of the plaque:according to CAS risk scoring system of IVUS-VH and Underhill, risk prediction and scoring of plaques are as follows: PB＜40%, low-risk plaque, score 1; PB＞40%, no lipid core, low-risk plaque, score 1; PB＞40%, lipid core＜20%, medium--low-risk plaque, score 2 points; 20%≤lipid core＜40%, medium-to-high-risks, score 3 points, and lipid core≥40%, high risk, score 4 points. Lipid core refers to low density area in plaques, CT value＜30Hu. When spotty calcification in the plaque is adjacent to or even broke into the lumen, it is also a risk factor, and the corresponding score should plus one.Judgment of Plaque vulnerability:Low-risk plaques are stable plaques, medium-low-risk to high-risk plaques are vulnerable plaques, among which medium low, medium high, high risk are low, medium, high fracture risk ranking of the vulnerable plaques.5. Using SPSS13.0 software package for statistical processing, summarize section numbers of plaque involvement in all 123 cases of hyperlipidemia patients, analyze plaque distribution and the high-risk plaque distribution; depict the scatter plot of the plaque area and vascular outer area, and sum the regression equation; compare the differences between relatively low risk plaques and vulnerable plaques RI, EI, PB, SR; Pearson correlation analysis between lipid risk stratification, TCH and LDL values and plaque scores; compare the differences between Plaques score, the number of vulnerable plaque, and high-risk vulnerable plaques of the following five groups, that is low risk of high lipid, medium risk, high risk, stable angina group and ACS group.Results:1.1 Uneven distribution of plaques, the easily affected was the following 1-7, that was 6,11,7,2,1,5,3 sections, in these plaques we had found 307 plaques, accounting for 90.3% of the total, the most likely involved was the 6th section, we had found plaques in the 6th section one among 87 patients, that was 71% patients get involved in the 6th section.1.2 Regression equation of Plaque area and vascular regression Y=6.951+0.902X (Y:VA X=PA) R SqLinear=0.643 because VA=LA+PA,thus we can infer LA=6.951-0.098PA 1.3 Different operators using the EDIT SECTION software according to the unified reference standard for the same group of patients with the same section of plaques evaluation of RI, EI, PB, SR, the difference was not statistically significant(t=0.0935,0.7974,0.8792,1.8474, P=0.9257,0.4268,0.3810,0.0671). Different operators using EDIT SECTION software based on unified reference standard for the same group of plaque vulnerability of judgment, the difference was not statistically significant (χ2=0.5, p=0.4788).1.4 Comparison between patients with low-risk plaque and vulnerable plaque RI, EI, PB, SR, there was no Statistical differences except EI differences(P>0.05), and RI, EI, PB, SR differences all had statistical significance (P<0.05) 2.1 There was no obvious relativity between TC, LDL-C numerical value and plaque score (r=0.004,0.049, p=0.591,0.967)and there is obvious relativity between lipid risk stratification and the plaque score (r=0.67, P=0.000). 2.2Low risk of high lipid, medium risk,high risk,stable angina group and ACS group, and plaque score of the five groups had statistical differences(F=34.150, P=0.000). By multiple comparison there were no statistical differences between stable angina and ACS (P＞0.05), but multiple comparisons between other groups had statistical significances (P＜0.05) 2.3 The vulnerable plaque number in the following five groups Low risk of high lipid, medium risk, high risk,stable angina group and ACS group have statistical (F=37.124, P=0.000), By multiple comparison there were no statistical differences between stable angina and high risk of high lipid, but multiple comparisons between other groups have statistical significances (P＜0.05); The high risk vulnerable plaque number in the following five groups Low risk of high lipid, medium risk, high risk, stable angina group and ACS group have statistical (F=30.219, P=0.000), By multiple comparison there were statistical differences between stable angina and high risk of high lipid group, stable angina and ACS group (P＜0.05).Conclusion:1.1 Coronary atherosclerotic plaques mainly occurs nearby the main branches of coronary artery, especially the left anterior descending coronary artery nearly section. The left coronary artery is more likely to be affected than the right coronary artery, especially the farther point of the left coronary artery. Distributions of the first, the second and the third section plaque on the right coronary artery are relatively even.1.2 The paper provides us with the regression equation of the relationship between VA and PA: Y=6.951+0.902X(Y:VA X=PA) R SqLinear=0.643. In accordance with LA=VA-PA, the author infers that LA=6.951-0.098PA, suggesting that the increase of PA/mm2, LA will only decrease by 0.098 correspondingly, and the remaining 90.2% will be compensated by the V expansion of VA.1.3 The establishment of a unified reference standards is the key ensure to the plaque measurement and vulnerability judgment with good reproducibility.1.4 The vulnerable plaques have higher RI, PB, SR than low-risk plaques, and SR of most of the vulnerable plaques is no more than 60%. The lowest SR of the high-risk vulnerable plaques under study is 19%.There is no statistics difference of El between vulnerable plaques and low-risk plaques.2.1 The LDL-C and TC of dyslipidemia patients are irrelevant to the risk of coronary atherosclerotic plaque. The dyslipidemia risk stratification of dyslipidemia patients is related to the risk of coronary atherosclerotic plaque.2.2 Among the dyslipidemia patients with atypical angina symptoms, the dyslipidemia risk stratification patients who are at intermediate risk should be considered as the intervention point of the CTA check of coronary heart disease risk in primary prevention coronary, and patients who are at high risk of coronary heart disease should be regarded as the key point of the CTA check of coronary heart disease risk in primary prevention coronary.2.3 Coronary CTA can display differences of number and structure of high-risk vulnerable plaques between coronary heart disease patients with stable angina and patients with ACS of of the difference, which provides the basis for clinical further examination (IVUS) and choices oft therapeutic schedule.