Utility Of Two-dimensional Speckle Tracking Echocardiography In Chemotherapy-induced Cardiac Injury

Part one Application of a combination of echocardiographic techniques in an experimental model of epirubicin-induced cardiotoxicityObjective:This study compared the potential ability of multinomial echocardiographic parameters in early detection,prediction and combined diagnosis of antineoplastic-related cardiotoxicity.Methods:Male Balb/c mice were repeatedly administered with low doses of epirubicin(6 ×3 mg/kg;n=20)to induce cardiac injury or with placebo as control(n=10).Conventional and strain parameters as well as myocardial performance index(MPI)were analyzed at baseline,1 day after the second,fourth and sixth cycle,and 12 days after completion of chemotherapy(as follow-up)by a high-resolution rodent ultrasound machine.After the experiment,serum cTnI levels were measured,and myocardial injury was evaluated by histological analyses.Results:Thirteen mice developed cardiotoxicity after epirubicin exp-osure.Global longitudinal(GLS),radial strain(GRS)and longitudinal strain rate(LSR)were markedly decreased(all P<0.01)and MPI was increased(P<0.05)at the completion of treatment compared with baseline values.GLS expressed the best correlations with myocardial pathological injury,especially with collagen content(ρ=-0.68,P<0.01).Additionally,GLS and MPI were associated with serum cTnI levels.A>9.5%decrease in GLS from baseline to the fourth cycle of chemotherapy could predict future cardiotoxicity(odds ratio=0.331,P<0.05).GLS(cutoff value,-15.16%)combined with MPI(cutoff value,0.64)could improve the accuracy of diagnosing cardiotoxicity(sensitivity,92%;specificity,87%).Conclusions:GLS was the only predictor of cardiotoxicity.GLS combined with MPI may provide a noninvasive and accurate method for the early detection of cardiotoxicity.Part two Predictive value of post systolic shortening by two-dimensional speckle tracking echocardiography on cardiac injury in the breast cancer patients after chemotherapyObjective:Post systolic shortening(PSS)has been proposed as a marker of regional contractile dysfunction in the myocardium.Our objective was to assess the prognostic potential of PSS on cardiac injury in the breast cancer patients after chemotherapy.Methods:This study was designed a prospective cohort study of 69 women with HER-2 negative breast cancer after chemotherapy who were followed up to observe the risk of cardiac injury.The post-systolic strain index(PSI)of each segment of left ventricular myocardium after chemotherapy was obtained by two-dimensional speckle tracking echocardiography.PSI(%)was defined as follows:[(peak strain in cardiac cycle-peak strain in systole)/peak strain in cardiac cycle]× 100.PSS was regarded as present and meaningful if PSI>20%.End point was cardiac injury,which could be manifested as cardiotoxicity,cardiogenic death,myocardial infarction,unstable angina pectoris,and severe arrhythmias.At least one of them happened,end point was considered to have occurred.According to the number of myocardial walls with PSS,the patients were divided into three groups:group(1)no PSS,group(2)1 wall,and group(3)≥ 2 walls.Additionally,the patients were also stratified according to tertiles of PSI.Results:During a median follow-up of 18 months(interquartile range,17-18 months),17 patients(24.64%)were diagnosed as having end point events.The risk of end point increased with the increase in the number of myocardial walls displaying PSS and the increase in PSI stratification.After adjusting for age,hypertension,systolic blood pressure,global longitudinal strain,and E peak of mitral early diastolic inflow velocity/average peak early diastolic mitral annular velocity e’(E/e’),the association remained significant,(Per 1 increase in number of walls displaying PSS,hazard ratio,1.96;95%confidence interval,1.23-3.39;P=0.007.Per 1%increase in PSI,hazard ratio,1.44;95%confidence interval,1.26-1.64;P<0.001).In terms of predictive ability,the Harrell’s C index of PSS and of PSI was 0.70 and 0.73,respectively,both P<0.01,which indicated moderate accuracy.Conclusion:The presence of PSS in breast cancer patients after chemotherapy can provide independent prognostic information for the future occurrence of cardiac injury.