Clinical Value Of Speckle Tracking Imaging In Evaluating Risk Stratification Of Patients Undergoing Coronary Artery Bypass Grafting

Purpose:To explore the application value of speckle tracking imaging in risk stratification of patients with coronary artery bypass grafting,and to promote the application of speckle tracking imaging in risk stratification of patients with coronary heart disease.Materials and methods:41 patients were selected for coronary artery bypass grafting and 20healthy subjects were selected as controls.All patients were stratified by the scoring system of SYNTAX and divided into two groups according to SYNTAXⅡscore:low-risk group（0-21 points）,and medium-high-risk group（≥22 points）.Transthoracic echocardiography measurements:left atrial diameter（LA）,left ventricular end-diastolic diameter（LVIDd）,left ventricular end-systolic diameter（LVIDS）,right ventricular end-diastolic diameter（RVIDd）,right ventricular end-systole diameter（RVIDS）,tricuspid annulus systolic displacement（TAPSE）,left atrial volume index（LAVI）,left ventricular ejection fraction（LVEF）,mitral annulus peak velocity ratio（Ea/Aa）in early and late diastole,right ventricular area change rate（RVFAC）.The apical long-axis two-dimensional dynamic images were acquired.Dynamic images were analyzed and measured using Q-lab 9.0workstation:left atrial longitudinal peak strain rates（mSRs,mSRe,mSRa）at systole,early and late diastole,left atrial systolic global longitudinal strain（GS）,left ventricular basal segment,middle segment and apical segment systolic longitudinal strains(GLS_Basal,GLS_Middle,GLS_Apical),left ventricular systolic global longitudinal strain（GLS）,Right ventricular basal segment,middle segment and apical segment systolic longitudinal strain(GLSS_Basal,GLSS_Middle,GLSS_Apical),right ventricular systolic global longitudinal strain（GLSS）,The systolic maximum displacement（Midpt）at the midpoint of the line connecting the interventricular septum and the mitral annulus on the left ventricular sidewall,and Midpt accounted for the percentage of left ventricular end-diastolic maximum longitudinal diameter（Midpt%）.Results:（1）Comparison of general clinical data between CABG group and control groupCompared with the control group,the high density lipoprotein in CABG group decreased with statistical significance（P<0.05）,while there was no significant difference in other clinical data（P>0.05）.（2）Comparison of transthoracic echocardiography parameters between CABG group and control groupLAVI in CABG group was higher than that in control group,and the difference was statistically significant（P<0.05）.There was no significant difference in other conventional transthoracic echocardiography parameters（P>0.05）.（3）Comparison of speckle tracking parameters between CABG group and control groupCompared with the control group,the mSRa in CABG group was increased,and the longitudinal strain values of right ventricle and left ventricle,Midpt,Midpt%,GS,mSRs and mSRe were decreased,with statistical significance（P<0.05）.Compared with the low-risk group,the mSRa in the medium-high-risk group was higher,and GLS,GLS_Basalasal and GLSS were significantly reduced（P<0.05）.（4）Comparison of the changes of relevant parameters after surgery in CABG groupsThe mSRa,GLS,GLS_Basal and GLSS were significantly improved in all CABG groups after surgery.The improvement values of mSRa,GLS,GLS_Basal and GLSS in the high-risk group were less than those in the low-risk group.The differences were statistically significant（P<0.05）,and the improvement value of GLS was the most significant（P<0.01）.Conculsions:1.Traditional transthoracic echocardiography can not detect the impairment of cardiac function in patients with coronary heart disease without obvious regional wall motion abnormalities.2.Speckle tracking imaging can sensitively diagnose myocardial systolic and diastolic dysfunction in patients with coronary heart disease,and can be used in combination with the scoring system of SYNTAX to improve the risk stratification of patients with coronary heart disease,providing more objective basis for risk stratification.3.Coronary artery bypass grafting can improve the cardiac function of patients with coronary heart disease,and the improvement degrees of cardiac function of medium-high-risk patients is obviously reduced.Global longitudinal strain has irreplaceable predictive value for the prognosis of coronary heart disease.