Application Of Layer Strain And Transmural Myocardial Strain Gradient Echocardiography In Non-ST-segment Elevation Acute Coronary Syndrome

Objective: The objective was to assess whether patients with non-ST-segment elevation acute coronary syndrome(NSTE-ACS)had reduced left ventricular function assessed by three layer-specific strains and transmural myocardial strain gradients compared with normal persons.Methods: Thirty-one patients referred to coronary angiography due to suspected nonST-segment elevation-acute coronary syndromes(NSTE-ACS)were prospectively included.Thirty-two normal people were set as a control group.Echocardiography was performed 1 to 2 hours before angiography.Layer-specific global longitudinal strains(GLS)and global circumferential strains(GCS)were assessed from endocardium(GLSendo,GCSendo),mid-myocardium(GLSmid,GCSmid),and epicardium(GLSepi,GCSepi)by 2-dimensional speckle-tracking echocardiography.GLS was calculated based on 17-segment LV model,whereas GCS was calculated based on 16-segment LV model.Transmural myocardial strain gradients were calculated by each layer's subtraction in GLS or GCS.Results: In the NSTE-ACS group and the normal group,the left ventricular GLS and GCS gradually decreased the inner-outer myocardial strain value(absolute value),the endocardial strain was the largest,and the epicardial strain was the smallest.The longitudinal strains of the endocardial,mid-myocardial,and epicardial in the NSTEACS group were lower than those in the normal groups(P < 0.05).The transmural myocardial strain gradient of the NSTE-ACS group is smaller than the normal group(P<0.05).The area under the ROC curve of NSTE-ACS myocardium was predicted by TMSG-GLS(endo-mid-epi)(AUC 0.80,P<0.001),and the sensitivity and specificity of NSTE-ACS were 90.30% and 59.40%.Conclusion: The transmural myocardial strain gradient was significantly reduced in NSTE-ACS;layer-specific strain echocardiography was beneficial to identify NSTEACS by detecting myocardial TMSG-GLS(endo-mid-epi).