左冠状动脉主干及其分支间的夹角与左冠状动脉斑块形成的相关性分析

Correlation of intersection angles among left main coronary artery and its branches with formation of atherosclerotic plaques

目的利用冠状动脉(冠脉)CT血管成像(CT angiography,CTA)探讨左冠脉主干(left main coronary artery,LM)、左前降支(left anterior descending branch,LAD)、左回旋支(left circumflex branch,LCX)三者间的夹角与局部斑块形成和分布特征之间的相关性。方法对127例行冠脉CTA检查患者进行回顾性研究,分为正常组44例和左冠脉病变组83例,病变组进一步分为LM组(18例)、近段组(57例)、中远段组(8例)。在重建图像上测量LM、LAD、LCX三者之间的夹角,分析左冠脉夹角与局部斑块形成和分布特征之间的相关性。结果 127例患者LM与LAD间的夹角和LAD与LCX夹角(分支角)呈负相关(r=-0.356,P<0.05);LM与LCX间的夹角和分支角也呈负相关(r=-0.662,P<0.05)。近段组分支角(90.9°±20.0°)与正常组(72.7°±16.7°)比较差异有统计学意义(P<0.05)。近段组LM与LCX夹角(117.8°±16.0°)与正常组(129.5°±15.9°)比较有明显差异(P<0.05)。LAD近段斑块形成与分支角呈正相关,和LM与LCX夹角呈负相关。当分支角>70°时,左冠脉斑块形成概率将会增加。结论分支角、LM与LCX间夹角均与LAD近段斑块的形成和分布相关,利用多层螺旋CTA能够为左冠脉斑块形成、风险预测及介入治疗术前提供无创、准确、快捷的相关特征信息。

Objective To investigate the relationship of the intersection angles among left main coronary artery（ LM）,left anterior descending branch（ LAD） and left circumflex branch（ LCX） with the formation and distribution of atherosclerotic plaques in the left coronary artery by 320-row computed tomography angiography（ CTA）. Methods A total of 127 patients receiving CTA examinations in our department from January to May 2014 were retrospectively analyzed and divided into a normal group（ n = 44）,and a left coronary artery lesion group（ n = 83） which were further divided into 3 sub-groups： an LM group（ n = 18）,a proximal group（ n = 57） and a middle and distal group（ n = 8）. The intersection angles among LM,LAD and LCX on the reconstructed images were measured,and then the relationships between the intersection angles among LM,LAD and LCX and the formation and distribution of atherosclerotic plaques were analyzed. Results In the 127 patients,the intersection angle between LM and LAD was negatively correlated with that（ the bifurcation angle） between LAD and LCX（ r =- 0. 356,P〈 0. 05）,and the intersection angle between LM and LCX was also negatively correlated with the bifurcation angle（ r =- 0. 662,P〈 0. 05）. There was significant difference in the bifurcation angle between the proximal group（ 90. 9° ±20. 0°） and the normal group（ 72. 7° ± 16. 7°）（ P〈 0. 05）,and the intersection angle between LM and LCX had significant difference between the proximal group（ 117. 8° ± 16. 0°） and the normal group（ 129. 5° ±15. 9°）（ P〈 0. 05）. The formation of plaques at the proximal segment of LAD was positively correlated with the bifurcation angle and negatively correlated with the intersection angle between LM and LCX. When the bifurcation angle was 70°,the probability of plaque formation at the left coronary artery was increased.Conclusion The bifurcation angle and the intersection angle between LM and LCX are correlated with the formation and distribution of the plaques at the proximal segment of LAD,and multi-slice CTA can provide relevant feature information for the left coronary artery plaque formation,risk prediction and preoperative interventional therapy in a non-invasive,accurate and fast manner.