超声心动图心肌收缩早期延迟时间指标对判断冠状动脉狭窄程度的价值

Value of Duration of Myocardial Early Systolic Lengthening Assessed by Echocardiogram on Defining the Degree of Coronary Artery Stenosis

目的:采用二维斑点追踪技术(2D-speckle tracking imaging,2D-STI)中心肌的收缩早期延迟时间指标对判断冠状动脉(冠脉)狭窄程度的价值.方法:对185例可疑冠脉狭窄患者在冠脉造影前48 h进行超声心动图检查,测量心肌的收缩早期延迟时间、纵向应变(longitudinal strain,LS)、径向应变(radial strain,RS)及圆周应变(circumferential strain,CS).根据冠脉造影结果分组:即冠脉无狭窄者为冠脉正常组(n=48),狭窄程度<50%者为轻度狭窄组(n=37),50%≤狭窄程度<70%者为中度狭窄组(n=55),70%≤狭窄程度<100%者为重度狭窄组(n=45).结果:与冠脉正常组比较,轻度狭窄组心肌的收缩早期延迟时间、纵向应变、径向应变及圆周应变无明显改变(P>0.05),中度狭窄组心肌的收缩早期延迟时间延长,纵向应变减低(P<0.05),重度狭窄组心肌的收缩早期延迟时间延长、纵向应变、径向应变及圆周应变均减低(P<0.01).ROC曲线显示,心肌的收缩早期延迟时间较纵向应变筛选冠脉中度、重度狭窄患者更佳.以收缩早期延迟时间为60.0 ms作为截断值时诊断价值最佳,敏感度为85.5%,特异度为74.1%,AUC=0.91.结论:中度以上的冠脉狭窄患者心肌的收缩早期时间明显延长,这一参数可准确识别不同程度冠状动脉狭窄患者.

Objectives: To evaluate the degree of coronary artery stenosis with duration of myocardial early systolic lengthening derived from 2D speckle tracking imaging (2D-STI) in patients with coronary artery disease (CAD). Methods: 185 patients with suspected CAD underwent 2D-STI before coronary CT angiography (CCTA) were included in this study. Duration of myocardial early systolic lengthening, LS, RS, and CS were measured by 2D-STI. According to the results of CCTA, the myocardial segment were divided into normal group (without coronary artery stenosis), mild stenosis group(coronary artery stenosis<50%), moderate stenosis group (50%≥coronary artery stenosis<70%) and severe stenosis group (70%≥coronary artery stenosis <100%). Results: Duration of myocardial early systolic lengthening, LS, RS and CS were similar between mild stenosis group and normal group (P﹥0.05). Duration of myocardial early systolic lengthening was increased, and LS was decreased in moderate stenosis group than in normal group (P<0.05). Duration of myocardial early systolic lengthening was increased, LS, RS and CS were significantly decreased in severe stenosis group than in normal group (P <0.01). The cutoff value of early systolic lengthening for diagnose severe stenosis was 60.0 ms (area under ROC curve [AUC]=0.91, P <0.01), with the sensitivity 85.5% and specificity 74.1%, respectively. Conclusions: Duration of myocardial early systolic lengthening is prolonged in patients with significant CAD (moderate and severe stenosis), and might be used a useful parameter to identify patients with significant CAD (moderate and severe stenosis).