MDCT评价冠状动脉狭窄程度与升主动脉弹性的相关性

The correlation between the severity of coronary artery disease and ascending aortic distensibility evaluated by 64-MDCT

目的:采用64-MDCT评价冠状动脉狭窄程度与升主动脉弹性的相关性。方法:病变组搜集120例冠状动脉狭窄患者,所有患者同时行64排螺旋CT冠状动脉成像和常规造影,对每支血管病变按狭窄程度分组、评价,并计算Gensini积分。CTA原始数据间隔5%R-R间期在0%～95%R-R间期重组图像,然后在主动脉窦上方约25mm层面采用MATLAB图像分割软件,分别测量各重建期相主动脉的横断面积。受检者完成CT扫描前后由专人常规测量血压。弹性值D[Pa-1]的计算公式为:D=ΔA/(A0.ΔP),ΔA代表管腔最大与最小面积的差值,A0代表心动周期内最小管腔面积,ΔP代表脉压差。选取经CTA证实冠状动脉无狭窄的健康志愿者25例为对照组,在CT检查前后一周内采用M型超声测量升主动脉的直径变化,并将计算的弹性值与CTA测得的弹性值进行比较。结果:64-MDCT与超声测量的主动脉弹性值间有极好的一致性(组内相关系数ICC=0.98,P<0.001)。正常对照组与病变组间弹性D值及PWV差异均有统计学意义(P=0.000)。冠状动脉狭窄的Gensini积分与弹性D值呈显著负相关(r=-0.83,P<0.01),与脉搏波速度(PWV)呈显著正相关(r=0.83、P<0.01)。冠状动脉狭窄程度随主动脉弹性D值的增加而递减,随PWV值的增加而递增。冠状动脉不同狭窄程度组间D值、PWV值、Gensini积分的均值比较,差异均有统计学意义(FD=79.29,FPWV=119.11,FG=128.07,P=0.000)。logistic回归分析显示主动脉弹性D是冠心病的独立影响因子。结论:64-MDCT评价冠状动脉狭窄程度的同时,可以客观评价升主动脉的弹性,升主动脉弹性的定量评价有助于检测亚临床冠状动脉血管病变及预测冠心病。

Objectlve：To evaluate the correlation between the severity of coronary artery stenosis and ascending aortic distensibility evaluated by MDCT.Methods：120 patients with coronary artery stenosis（disease group） underwent 64-MDCT coronary angiography and routine coronary angiography,each vessel segment was analyzed and grouped according to stenosis extent and coronary artery Gensini score were calculated.The primary scan data of CTA were reconstructed between 0% and 95% of the R-R intervals with an increment of 5%.Cross-sectional areas were calculated at the ascending aorta about 25mm above aortic valve with image segmentation software MATLAB.Blood pressure was measured before and after CT scan and the average value of the two was adopted.Aortic distensibility（AD） was calculated as follows：D=ΔA/（A0·ΔP）.25 healthy volunteers with normal coronary artery（normal group） confirmed by CTA was included as control group,Aortic diameter was measured by 2D-transthoracic echocardiography（TTE） in no more than a week with CTA scan to calculate the AD which was compared with AD measured by CTA.Results：There was an excellent consistency between CTA and TTE measured AD（ICC=0.98,P0.001）.D value and PWV value of normal group and disease group had significant difference（P0.000）.Severity of coronary artery（Gensini score） exhibited a strong negative correlation with aortic distensibility（r=-0.83,P0.01） and positive correlation with pulse wave velocity（PWV）.The severity of coronary artery stenosis decreased proportionally with AD,and increased proportionally with pulse wave velocity（PWV）.D value,PWV value and Gensini score among various degrees of coronary stenosis（4 groups） had significant difference（FD=79.29,FPWV=119.11,FG=128.07,P=0.000）.Binary logistic regression showed aortic distensibility is an independent factor of coronary heart disease.Conclusion：Aortic distensibility can be calculated objectively with 64-MDCT in evaluating coronary stenosis.Quantitative evaluation of ascending aortic distensibility is useful in detecting subclinical coronary vascular lesions and predicting coronary heart disease.