The Distribution Of Cardial Adipose Tissues And Coronary Artery Disease

Objectives:The aims of the study were to evaluate the association between fat distribution and coronary artery disease(CAD)by coronary computed tomographic angiography(CCTA)method,and compare it with traditional risk factors for CAD.Then,we tried to establish a diagnostic model of multiple risk factors for CAD.Methods:In this single centre study,we consecutively enrolled 688 inpatients with preliminary diagnosis of CAD undergone CCTA in our hospital.Then the subjects were divided into two groups,CAD group(n=488,59.8±9.13 years old)and Control group(n=200,58.9±8.14 years old).The volume of EAT and PAT,the thickness of fat of left ventricular free wall and right ventricular free wall,and the volume and thickness of the fat around the left anterior descending(LAD),left Circumflex(LCX)and right coronary artery(RCA)were measured by cardiac computer tomography(CT).As part of the study,subjects underwent cardiac computed tomography(CT)for quantification of CAC.The fat surrounding a coronary segment was manually traced in axial planes.Other coronary vessels and segments,myocardium,and the pericardial sac were defined as borders for the region of interest.For EAT volume quantification,the pericardium was manually traced on every single cross-sectional image from the level of the pulmonary artery bifurcation to the diaphragm.The CT attenuation threshold of-190 Hounsfield units(HU)to-30Hounsfield units(HU)was used to distinguish EAT with other tissues.After three-dimensional reconstruction,fat volumes were automatically calculated by the software program.Results:1 Clinical features:compared with the Control group,the CAD group had more male patients[61.9%(302/488)vs 37.0%(74/200),P<0.001].And the prevalence of hypertension(HTN),type 2 diabetes mellitus(T2DM),ischemic strok,former smoking,current smoking and heavy alcohol intake were significantly higher in CAD group than those in Control group[68.3%(319/467)vs46.4(89/192);23.3%(108/464)vs12.6%(24/190);15.37%(75/488)vs6.5%(13/200);32.1%(150/468)vs19.1%(37/194);39.5%(185/468)vs21.6%(42/194);24.6%(115/467)vs 15.5%(30/194),all P<0.05].2 The distributions of cardial adipose tissues:2.1 PAT and EAT volume in CAD group were significantly higher than those in the control group,246.0(184.0,324.3)cm~3 vs 193.5(149.3,238.0)cm~3;131.0(89.1,223.0)cm~3 vs100.0(72.4,128.0)cm~3,respectively(all P<0.05).The thickness of the fat around left ventricular free wall fat and right ventricular free wall were more than the control group 5.0(3.5,7.0)mm vs5.0(3.7,7.0)mm;3.0(1.9,4.2)mm vs 3.2(1.8,4.7)mm,without significance(all P>0.05).2.2 CAC Score and Framingham Score of CAD group were significantly higher than those in the control group,were179.8(21.3,347.8)vs0.0(0.0,0.0);131.0(89.1,223.0)cm~3 vs 100.0(72.4,128.0),the differences were not significant(all P>0.05).2.3 The volume and thickness of the fat around the left anterior descending(LAD),left Circumflex(LCX)and right coronary artery(RCA)were significantly higher than those in the control group,10.0(8.0,12.1)mm vs 9.1(7.2,10.8)mm;15.7(10.8,21.1)cm~3 vs 12.6(8.1,16.9)cm~3,14.8(12.8,17.4)mm vs 13.0(10.4,14.8)mm;6.3(4.0,9.1)cm~3 vs 5.0(3.0,7.3)cm~3,18.6(16.1,21.6)mm vs 18.2(15.6,21.1)mm;27.3(20.6,36.7)cm~3 vs 24.9(17.7,32.1)cm~3(all P>0.05).3 Spearman correlation analysis:3.1 The volume of EAT was positively correlated with hypertension,hyperlipidemia,T2DM,ischemicstroke and CAC Score(Rs=0.146;0.083;0.149;0.098;0.155),the differences were statistically significant(all P<0.05).3.2 The volume of PAT was positively correlated with hypertensi on,hyperlipidemia,T2DM,ischemic stroke and CAC Score(Rs=0.156;0.108;0.178;0.108;0.134),the differences were statistically significant(all P<0.05).4 ROC curve analysis showed that the areas under the curve of EAT,PAT,the thickness of fat around LAD,the fat volume of LAD,the t hickness of fat around LCX,the fat volume of LCX,the thickness of fat around RCA and the fat volume of RCA in the diagnosis of CAD wer e0.663(95%CI:0.622,0.704),0.665(95%CI:0.622,0.708),0.594(95%CI:0.546-0.642),0.617(95%CI:0.559,0.675),0.707(95%CI:0.654,0.759),0.586(95%CI:0.502,0.611)and 0.556(95%CI:0.532,0.641)(all P<0.05);the cut-off p oints were 171.5cm~3,240.5cm~3,11.0mm,15.5cm~3,14.2mm,8.7cm~3、24.7mm、31.3cm~3;the sensitivities were37.2%,52.7%,37.6%,51.5%,58.2%,29.1%,14.1%,and 40.0%,repectively.And the specificities of diagnosis were94.0%,76.5%,78.0%,70.0%,70.3%,87.2%,96.0%and 74.5%,repectively(all P<0.05).5 Multiple risk factors model analysis.In the multi-factor regression model,dyslipidemia,hypertension,type 2 diabetes,smoking history,history of stroke and EAT capacity were all independent risk factors of CAD.And the Oddsratioswere2.322(95%CI:1.577,3.420),2.087(1.427,3.052),1.765(1.046,2.976),2.650(1.758,3.995),3.113(1.521,6.371),2.566(1.710,3.851),repectively(all P<0.05).6 Logistic regression analysis of the association of EAT Volume wi th CAD in CAC=0 subgroup showed that after adjustment of BMI,age,s ex,hypertension,hyperlipidemia,T2DM,ischemic stroke,former smoker,curr ent smoker,TC and TG,the odds ratio was 1.860 with 95%CI(1.226-2.821),P<0.05).Conclusions:1 The volume of EAT and PAT increased significantly in the CAD group than the control group,indicating that the inflammatory hyperplasia of EAT and PAT were independent risk factors of CAD.2 In the three subgroups of LAD,LCX and RCA stenosis,the volumes of the fat around the main coronary arteries branches in the CAD group increased significantly than the control groups.And the adiposes of right ventricular free wall and left ventricular free wall have no significant increases between the two groups.Therefore,we figured out that the LAD,LCX and RCA fat inflammatory hyperplasia were independent risk factors of CAD.3 Logistic regression analysis of the association of EAT Volume i n CAC=0 subgroup showed that EAT and/or PAT inflammatory hyper plasia were soundly independent risk factors of CAD in the absence of coronary artery calcification.4 EAT and PAT volume levels were positively correlated with traditional CAD risk factors,such as hypertension,dysplasia,type 2 diabetes,ischemic stroke and high CAC score.In conclusion,cardial adipose tissues inflammatory hyperplasia,as an independent risk factor for CAD,may be used as a new marker for the diagnosis of CAD.