Study Of Coronary Artery Calcification Morphology Assessed By Intravascular Ultrasound

Objective:This study is aimed at evaluating the morphological features of coronary artery calcified plaque(CACP)of ischemic lesion segments with the assistance of Intravascular ultrasound(IVUS)technique.and at analyzing the correlation between coronary artery calcification(CAC)and plaque morphology(PM)or general clinical cardiovascular risk factors(CRFs),so to provide theoretical reference for clinical prevention and treatment of coronary atherosclerotic disease(CAD)complicated with CAC.Methods:85 cases of consecutive patients who were admitted and diagnosed as coronary atherosclerotic disease(CAD)from Nov.2015 to Feb.2017 and underwent IVUS examination before coronary angiography(CAG)and percutaneous coronary intervention(PCI)treatment were enrolled in this study.After collection of 85 blood vessels of target lesions,a quantitative analysis and a qualitative analysis were made on coronary artery calcified plaque of lesion segments in order to obtain cardiovascular calcium index(CalcIndex)and indicators.According to the cardiovascular calcium index.the patients were assigned into 2 groups:0-lower cardiovascular calcium index group and moderate-higher cardiovascular calcium index group.The differences of general clinical CRFs and PM parameters between these two groups were compared.And Spearman linear correlation analysis was used to analyze the correlations between some clinical CRFs and PM or CalcIndex.Results:1.The histories of hypertension,diabetes mellitus and family history of CHD between 0-lower Calclndex group(CalcIndex?0.140,n = 56)and moderate-higher CalcIndex group(CalcIndex>0.140,n = 29)were statistically significant;while the intergroup differences of gender,age,body mass index(BMI),acute coronary syndrome(ACS),smoking history,statins history were not statistically significant;the linear correlation analysis showed no significant correlation between age,weight,height or BMI and Calclndex.2.There was significant difference in homocysteine(HCY)between these two groups;while the intergroup differences of low density lipoprotein cholesterol(LDL-C),serum creatinine(Scr)and estimated glomerular filtration rate(eGFR)were not statistically significant;in the linear correlation analysis for correlation between LDL-C,HCY,Scr,eGFR and CalcIndex,there was a positive correlation between HCY and Calclndex,while there was no significant correlation between LDL-C,Scr or eGFR and Calclndex.3.Ischemic lesion segments were mainly in left anterior descending(LAD)branch(including its subbranch)(n = 47),accounting for 55.3%.The intergroup differences in anatomical position distribution of ischemic lesion segments were not statistically significant.4.In all plaques of narrowest parts of ischemic lesion segments,CACPs accounted for 88.2%(n =75).For CACP types,superficial calcifications(n = 55)accounting for 73.3%in calcified plaques,and the intergroup distribution difference of superficial calcifications was statistically significant;vascular remodeling analysis showed that negative remodeling(N = 32)was dominant,accounting for 37.6%,the intergroup difference in proportion of negative remodeling was statistically significant.5.The intergroup differences in length of lesion segments,reference diameter,minimal lumen area(MLA),external elastic membrane cross-sectional area(EEM-CSA),plaque burden(P.B),plaque eccentricity index,lumen stenosis rate,maximum calcification angle(MaxCal)and distances between MLA positions were not statistically significantly,but when MLA was smaller,there was a trend towards moderate-higher CalcIndex group;further the linear correlation analysis showed MLA and CalcIndex was negatively correlated.Conclusion:1.CAC is a result from the combination of multiple CRFs.In all concurrent CRFs of CHD patients,ischemic lesions segments of patients with CHD family history,histories of hypertension,diabetes and high-level HCY show higher CalcIndex,while gender,age,BMI,ACS,history of smoking or statins therapy history show no significant correlation to CAC.2.Ischemic lesion segments are mainly in LAD(including its subbranch),while the anatomical position of the ischemic lesion segments was not significantly correlated with CAC;the length of lesion segments,reference diameter,EEM-CSA,P.B,plaque eccentricity index,lumen stenosis rate,maxCal or distances between MLA positions has no significant correlation to CAC.Not all narrowest parts of the ischemic lesion segments were located at the maxCal positions,and the degree of calcification has no significant correlation to lumen stenosis rate,but it was confirmed that there is a negative correlation between MLA and CAC in ischemic lesion segments.3.IVUS technique can be used to better determine the type of CACP,and in all types of CACP in ischemic lesion segments,superficial and medial calcifications are dominant;vascular remodeling analysis showed that negative remodeling is dominant.Through an linear correlation analysis on correlation between indicators of anatomical morphology or PM of coronary ischemia lesion segments and CAC,it can provide a reference for strategy-making in clinical prevention and treatment of CHD complicated with CAC.