Prediction Of Severe Coronary Artery Stenosis In Patients With Coronary Heart Disease Using Noninvasive Myocardial Work Evaluation Stress Echocardiograph

Part ⅠThe Characteristics of Noninvasive Myocardial Work Indices in Healthy Adults at Baseline and After Exercise StressObjectives:To explore the characteristics of the myocardial work(MW)parameters noninvasively evaluated by the left ventricular pressure-strain loop(PSL)and explore the influence factors of MW in healthy adults at baseline and after exercise stress.Methods:35 healthy adult volunteers(age 49±12 years;male:43%)were consecutively enrolled from August 2019 to January 2020 for physical examination;21 subjects(male:48%)underwent treadmill exercise stress.PSL were used to assess MW including global myocardial work index(GWI),global myocardial work efficiency(GWE),global myocardial constructive work(GCW)and global myocardial wasted work(GWW).Correlation between continuous variables was performed using Pearson’s or Spearman’s correlation coefficient,as appropriate.Multivariate linear regression analysis was used to evaluate the independent correlation between.The agreements were assessed by intraclass correlation coefficients and the Bland-Altman method.Results:At baseline,men had higher values of GWW and lower values of GWI,GCW,and GWE than women but the differences were not statistically significant.After treadmill exercise stress,the values of GWI,GCW and GWW significantly increased but GWE decreased in women(P<0.05);the values of GWI and GCW in men were significantly higher than those at baseline(P<0.05).At baseline,GWI and GCW were independently correlated with global longitudinal strain(GLS),systolic blood pressure,and diastolic blood pressure;GWW and GWE were independently correlated with peak strain dispersion and GLS.After treadmill exercise stress,GWI and GCW were independently correlated with systolic blood pressure;GWE was independently correlated with peak strain dispersion.The intra-class correlation coefficients and Bland-Altman plot both showed good repeatability in MW parameters at baseline and after exercises stress.Conclusions:The study presents the characteristics of noninvasive MW indices and demonstrates the good repeatability of MW indices in healthy adults at baseline and after exercise stress.MW parameters derived from the PSL allow noninvasive assessment of myocardial contractility and synchronization.Part ⅡGlobal Myocardial Work Combined with Treadmill Exercise Stress to Predict Significant Coronary Artery DiseaseAims:Accurate detection and effective intervention of significant coronary artery disease(CAD)are crucial to prevent adverse cardiac events and improve patient prognosis.Myocardial work(MW)derived from the left ventricular pressure-strain loop(PSL)is a novel and noninvasive method for assessing left ventricular function that accounts for loading conditions.We aimed to explore whether global MW combined with treadmill exercise stress could predict significant CAD in patients with angina pectoris.Methods:Eighty-five patients with angina pectoris and no prior CAD history were prospectively included.All patients underwent treadmill exercise stress echocardiography and coronary angiography.Global MW was constructed from global longitudinal strain indexed to the brachial systolic blood pressure,which created PSL.The Logistic regression were used to explore whether global MW parameters could predict significant CAD.The discriminative power of MW parameters to predict significant CAD was assessed with receiver operative characteristic curve,net reclassification improvement and integrated discrimination improvement analysis.Results:41 patients had significant coronary artery stenosis(≥70%in one or more major epicardial vessels or≥50%in the left main coronary artery).The global wasted work(GWW)and global work efficiency(GWE)was significantly higher or lower,respectively,in significant CAD group compared with those of non-significant CAD during the peak exercise and recovery periods(P<0.05 for all).Multivariate Logistic regression analysis demonstrated that peak GWE(OR=0.76,P=0.010),and recovery GWW(OR=1.009,P=0.045)could predict significant CAD.Peak GWE had the highest area under the receiver operating characteristic curve(AUC)among all global MW parameters(AUC=0.836).Furthermore,a model comprising peak GWE and recovery GWW performed better in prediction of significant CAD than peak GWE alone(AUC=0.856).Conclusion:Peak GWE could predict significant CAD.The new model,incorporating peak GWE and recovery GWW,could predict significant CAD better.Global MW parameters derived from PSL combined with exercise stress perform as an accurate noninvasive screening before the invasive diagnostic technique.Part ⅢComparison of Myocardial Layer-Specific Strain and Global Myocardial Work During Treadmill Exercise Stress in predicting Significant Coronary Artery DiseaseAims:The study aimed to compare the value of Global myocardial work efficiency(GWE),global myocardial wasted work(GWW)and myocardial layer-specific strain during treadmill exercise stress testing to predict significant coronary artery disease(CAD)with normal baseline wall motion and angina pectoris.Methods:Stress echocardiography was performed 7 days before angiography.Global longitudinal strain(GLS),myocardial layer-specific longitudinal strains and myocardial work were assessed by 2D speckle-tracking echocardiography.Logistic regression analyses were performed to evaluate whether the echocardiographic parameters could predict significant CAD.The discriminative power of the echocardiographic parameters to predict significant CAD was assessed with receiver operative characteristic curve,net reclassification improvement and integrated discrimination improvement analysis.Results:Forty-two patients were diagnosed with significant CAD,and 46 were defined as non-significant CAD.Patients with significant CAD had the worse function in all three myocardial layers at peak exercise compared with those with non-significant CAD when assessed with GLS.At the peak exercise and recovery periods,GWE was lower in patients with significant CAD than in patients with non-significant CAD.In multivariable logistic regression analysis,peak endocardial GLS(OR:1.28,P=0.030),peak GWE(OR:0.77,P=0.004)and recovery GWW(OR:1.009,P=0.031)could predict significant CAD.Receiver operating characteristic curves showed peak GWE to be superior to midmyocardial and epicardial GLS in predicting significant CAD.Further,adding peak GWE to endocardial GLS could improve the predictive capabilities.The predictive performance of the model comprising peak GWE,recovery GWW and peak endocardial GLS was further improved,with an area under the curves of 0.874,which was not better than the model comprising peak GWE and recovery GWW.Conclusion:The endocardial GLS was a good parameter to assess exercise stress echocardiography in predicting significant CAD.The combined model of MW parameters and endocardial GLS was significantly better than the single layer-specific strain parameter in predicting significant CAD,but not better than the original MW model.Part ⅣComparison of the value of treadmill exercise stress echocardiography combined with post-systolic shortening index,early systolic lengthening index and global wasted work in the prediction of significant coronary artery diseaseAims:This study intends to compare the value of treadmill exercise stress echocardiography combined with post-systolic shortening index(PSI),early systolic lengthening index(ESI)and global wasted work(GWW)in the prediction of significant coronary artery disease(CAD)in patients with suspected angina pectoris without previous history of coronary artery disease and resting wall motion abnormalities.Methods:The study prospectively included 88 patients.All patients underwent treadmill exercise stress echocardiography and coronary angiography(CAG).Speckle tracking imaging were used to analyzed the images,including global longitudinal strain(GLS),PSI,ESI and myocardial work(MW).Person or Spearman correlation was used to analyze the correlation between echocardiographic parameters.Logistic regression analysis were performed to explore whether the myocardial paradoxical deformation parameters could predict significant CAD.A receiver operating characteristic curve was used to assess and compare the capability of PSI,ESI and GWW to predict significant CAD.Results:According to CAG results,42 patients were included in the significant CAD group,and 46 patients were included in the non-significant CAD group.The peak PSI of the patients in the significant CAD group were significantly greater than that in the nonsignificant CAD group.Although the peak ESI of the significant CAD group was greater than that of the non-significant CAD group,there was no significant difference.The peak GWW and recovery GWW of the significant CAD group were significantly higher than those of the non-significant CAD group.In the multivariate regression analysis,only peak GWW had predictive value.The receiver operating characteristic curve analysis showed that GWW was superior to predicting significant CAD than wall motion score index(WMSI),GLS and PSI(area under the curve:0.813 vs.0.708,0.693,0.614;P<0.05).Conclusion:The peak PSI has a moderate predictive ability for significant CAD,which is better than the traditional WMSI,but slightly worse than peak GLS and peak GWW,and which is not enough to be used as a single predictor.GWW is a promising novel approach for non-invasive CAD screening.