左心室压力-应变环对非ST段抬高型急性冠脉综合征的诊断价值

Value of left ventricular pressure-strain loops in diagnosis of non-ST-segment-elevation acute coronary syndrome

目的应用左心室压力-应变环评估无明显节段性室壁运动异常且左室射血分数(LVEF)正常的非ST段抬高型急性冠脉综合征(NSTE-ACS)患者左室整体心肌做功,探讨其在NSTE-ACS诊断中的价值。方法入选2019年6-12月首都医科大学附属北京朝阳医院就诊的169例LVEF正常(>55%)的无明显节段性室壁运动的NSTE-ACS患者。依据冠脉造影结果,任意1支心外膜下冠脉直径狭窄≥70%的患者为单支冠脉严重狭窄组(52例),2支及以上心外膜下冠脉直径狭窄≥70%的患者为多支冠脉严重狭窄组(69例),<70%的患者为非严重狭窄组(48例)。冠脉造影前应用二维斑点追踪超声心动图进行整体纵向应变(GLS)分析,再将袖带血压作为左室压力构建无创左室压力-应变环,计算并比较各组整体心肌做功指数(GWI)、整体有效做功(GCW)、整体无效做功(GWW)和整体做功效率(GWE)。通过受试者工作特征(ROC)曲线分析,确定各参数预测患者发生冠脉严重狭窄的最佳截点值,并通过Logistic回归分析得出影响左室心肌功能的独立影响因素。结果与非严重狭窄组相比,冠脉严重狭窄组GLS、GWI、GCW、GWE显著降低,GWW显著增高(均P<0.05)。GLS在多支冠脉严重狭窄组显著降低(P<0.05),而在单支冠脉严重狭窄组无明显降低(P=0.32)。GWE是NSTE-ACS心肌功能的独立影响因素,GWE<96%作为诊断冠脉严重狭窄的截点值,ROC曲线下面积(AUC)=0.83(敏感性为74%,特异性为81%),优于GLS(AUC=0.66,P<0.05)和GWI(AUC=0.70,P<0.05)。结论在LVEF正常的无明显节段性室壁运动异常的NSTE-ACS冠脉严重狭窄患者中,基于无创压力-应变环的左室心肌做功受损,GWI、GCW、GWE降低,GWW增高。GWE可作为预测NSTE-ACS冠脉严重狭窄患者的敏感指标,且预测价值优于GLS和GWI。

Objective To assess global myocardial work in non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) patients with no obvious regional wall motion abnormalities and preserved left ventricular ejection fraction (LVEF) by noninvasive left ventricular (LV) pressure-strain loops, and to explore its diagnostic value in patients with NSTE-ACS.Methods A total of 169 NSTE-ACS patients with normal wall motion abnormalities and LVEF (>55%) were recruited in Beijing Chao Yang Hospital, Capital Medical University from June to December 2019. The patients were divided into two groups according to the degree of coronary stenosis, including severe coronary artery stenosis group (n=121), and no severe stenosis group (n=48). The patients of severe coronary artery stenosis group were further subdivided into single-vessel severe stenosis group (n=52) and multi-vessel severe stenosis group (n=69). Global longitudinal strain (GLS) analysis was performed by speckle tracking echocardiography before coronary angiography. Brachial cuff systolic pressure was used as left ventricular pressure to construct a non-invasive left ventricular pressure-strain loop. Global myocardial work index (GWI), global constructive work (GCW), global waste work (GWW) and global myocardial work efficiency (GWE) was computed by LV pressure-strain loops with a proprietary algorithm between groups. ROC curve analysis was used to determine the optimal cutoff value of the parameters to detect severe coronary artery stenosis. Independent factors affecting left ventricular myocardial function were assessed by Logistic regression analysis.Results GLS, GWI, GCW and GWE were significantly reduced, and GWW was increased in severe coronary artery stenosis group than in no severe stenosis group(all P<0.05). GLS was significantly reduced in multi-vessel severe stenosis group (P<0.05) but not in single-vessel severe stenosis group (P=0.32). GWE was an independent factor affecting myocardial function in severe coronary artery stenosis group, GWE<96% had a area under the curve (AUC)=0.83 (74% for sensitivity, 81% for specificity) to identify severe coronary artery stenosis, and was superior to GLS (AUC=0.66, P<0.05) and GWI (AUC=0.70, P<0.05).Conclusions In NSTE-ACS patients with severe coronary artery stenosis, no obvious regional wall motion abnormalities and preserved LVEF, LV global myocardial function is impaired based on noninvasive pressure-strain loops, GWI, GCW, and GWE are reduced, and GWW is increased, and GWE is a more sensitive index than GLS and GWI to predict severe coronary artery stenosis in NSTE-ACS patients.