二维纵向应变对室壁运动正常患者冠状动脉左主干和三支病变的预测价值

The Value of Two-dimensional Longitudinal Strain for Predicting Left Main and Three-vessel Coronary Artery Disease in Patients With Normal Wall Motion

目的:应用二维斑点追踪显像(2D-STI)技术评价室壁运动正常的不同程度冠状动脉病变患者左心室心肌纵向应变,探讨不同应变参数对冠状动脉左主干和三支病变的预测价值。方法:选取92例可疑冠心病患者,根据冠状动脉造影结果分为:冠心病高危组(左主干或三支病变)24例,冠心病低危组(单支或双支病变)36例和对照组(无冠心病)32例。应用自动功能成像技术获取左心室基底段纵向应变、中间段纵向应变、心尖段纵向应变、基底段+中间段纵向应变以及左心室整体纵向应变。比较三组间各常规超声参数和二维纵向应变参数的差异,利用受试者工作特征(ROC)曲线分析各应变参数对冠状动脉左主干和三支病变的预测价值。结果:随着冠状动脉病变程度加重,对照组、冠心病低危组、冠心病高危组的左心室基底段纵向应变、中间段纵向应变、心尖段纵向应变、基底段+中间段纵向应变以及左心室整体纵向应变均逐渐减低,上述指标冠心病低危组均低于对照组,冠心病高危组均低于冠心病低危组(P均<0.01)。ROC曲线分析显示,左心室基底段+中间段纵向应变预测冠状动脉左主干和三支病变的曲线下面积最大,为0.870,最佳界值为-18.1%(敏感度83.3%,特异度76.5%)。结论:在静息状态下室壁运动正常的冠心病患者中,左心室各水平及整体纵向应变随冠状动脉病变程度加重逐渐减低,二维纵向应变可较敏感地发现心肌缺血,左心室基底段+中间段纵向应变对冠状动脉左主干及三支病变的预测价值最大。

Objectives: To assess left ventricular(LV) longitudinal strain in patients with different degrees of coronary artery disease(CAD) and normal wall motion by two-dimensional speckle tracking imaging(2D-STI), and to explore the value of different strain parameters for predicting left main and three-vessel CAD in this patient cohort.Methods: Ninety-two patients with suspected CAD were enrolled. According to the coronary angiography(CAG) results, patients were divided into 3 groups: high-risk group with left main or three-vessel CAD(n=24), low-risk group with one-or two-vessel CAD(n=36) and control group without CAD(n=32). LV longitudinal strain of basal level(GLSbas), middle level(GLSmid), apical level(GLSapx), basal plus middle level(GLSbasmid) and global level(GLS) were obtained by automated function imaging(AFI). The conventional echocardiographic parameters and the two-dimensional(2D) longitudinal strain parameters were compared between the three groups and the receiver operating characteristic(ROC) curve analysis of these strain parameters was used to predict left main and three-vessel CAD.Results: GLSbas, GLSmid, GLSapx, GLSbasmid and GLS decreased with the increasing severity of CAD. GLSbas, GLSmid, GLSapx, GLSbasmid and GLS were significantly lower in CAD low-risk group than in control group(all P<0.01). GLSbas, GLSmid, GLSapx, GLSbasmid and GLS were significantly lower in CAD high-risk group than in CAD low-riskgroup(all P<0.01). GLSbasmid showed the highest area under ROC curve(0.870) for predicting left main and three-vessel CAD, with the optimal cut-off value of-18.1%(sensitivity 83.3%, specificity 76.5%). Conclusions: LV longitudinal strain of basal, middle and apical level and global level all decreased with the increasing severity of the CAD in patients with normal wall motion at rest. 2D longitudinal strain is sensitive to detect myocardial ischemia, LV GLSbasmid is the most valuable parameter for predicting left main and three-vessel CAD in this patient cohort.