Evaluation Of Two-dimensional Speckle Tracking Imaging In Differential Diagnosis Of Myocardial Ischemia Assessed With Model Of Logistic Regression

Objective:To investigate the clinical value of identifying contractile dysfunction of early myocardial ischemia by two-dimensional speckle tracking imaging(2D-STI) assessed with logistic regression predictive model.Material and Methods:According to the results of coronary angiography, the patients with myocardial ischemia were divided into 3 groups based on the extent of main left anterior descending(LAD) stenosis which were group A with 25 patients (no stenosis or stenosis<50%), group B with 21 patients ((stenosis 50%～75%), and group C with 25 patients (stenosis 75～99 %). Two-dimensional echocardiography images were recorded from the left ventricular short-axis views and the apical long-axis views of the left ventricle(LV) within one week before coronary angiography. The peak systolic circumferential, radial strain, longitudinal strain and strain rate of the 11 myocardium segments blood-supplied by LAD were analyzed by the Echo-PAC workstation. Analyze the receiver operating curve(ROC) and establish logistic regression predictive equation.Results:①There were no significant difference in each strain and propotional territorial strains in most segments between group A and group B(P>0.05). The peak systolic circumferential strain, longitudinal strain and strain rate, and each propotional territorial strains in most segments of group C (8/11～10/11) were significantly reduced (P<0.05 or P<0.01) when compared with group A and group B. However, there were no statistical significant difference in the peak systolic radial strain and territorial radial strains in most segments (9/11) of group C compared with group A and group B (P>0.05).②The diagnostic value of each territorial strains was more propitious to LAD stenosis≥75% than to LAD stenosis>50%. Based on ROC analysis, the area under the curve(AUC) of territorial longitudinal strain(TSL) was the biggest(0.825) compared with other indexes, and its diagnostic value was the highest.③The binary logistic regression equation of TSC and TSL discriminated LAD stenosis>75% and LAD stenosis<75% was p=1/[1+e-(632-0.15 TSC-0.22 TSL)], The AUC of the regression equation was 0.861, The cutoff value of predictive value was 0.30 with a sensibility of 84%, specificity of 82%, respectivelyConclusion:2D-STI could assess the LV contractile dysfunction of early myocardial ischemia in CHD patients. The logistic regression equation of TSC and TSL could be used for the primarily diagnosis of CHD with LAD stenosis≥or<75%.