Early Evaluation Of Left Ventricular Myocardial Injury In Multiple Myeloma By Two-dimensional Speckle Tracking Imaging

BackgroundMultiple myeloma(MM)represents about 1%of all malignant tumors and is a monoclonal disease of the blood system originating in bone marrow plasma cells.MM is usually more common in the elderly,myocardial injury mainly with amyloidosis,high viscosity syndrome,anemia and kidney injury,mainly affect the structure and function of left ventricle,characterized by left heart failure and arrhythmia,seriously affect the patients life quality and survival period.Therefore,early sensitive assessment of changes in left ventricular structure and function in patients with MM has important clinical significance.Left ventricular diastolic function is abnormal in patients with MM by echocardiography,and left ventricular ejection fraction(LVEF),which is used to evaluate the global left ventricular systolic function,is usually maintained at normal level in the early stage of disease.Strain indicators obtained by two-dimensional speckle tracking imaging(2D-STI)have also been used to evaluate left ventricular systolic function in recent years.Longitudinal strain(LS)should be sensitive to detect potential left ventricular systolic dysfunction before LVEF decrease compared with radial and circumferential.Layered(endocardial,middle and epicardial),segmental(basal,middle and apical)longitudinal strain(LS)and myocardial mechanical synchrony indicator peak strain dispersion(PSD),It can sensitively detect early changes in regional myocardial function and movement coordination,and can comprehensively evaluate left ventricular systolic function combined with myocardial deformation and mechanical movement.However,load dependence is the biggest deficiency of LS in evaluating left ventricular systolic function.Left ventricular pres sure-strain loop(PSL)is a new ultrasonic diagnostic technology,which can effectively solve the impact of load dependence and non-invasive assessment of left ventricular myocardial systolic function.ObjectivesUsing 2D-STI and PSL,a comprehensive analysis of indicators such as layered and segmented LS,PSD,and LVMW was performed in MM patients with preserved LVEF,the changes in myocardial deformation,mechanical motion,and work were integrated to comprehensively assess the global and segmental systolic function of the left ventricle.The correlation between LS indicator and brain natriuretic peptide(BNP)was also analyzed,In order to provide a reliable imaging evidence for early diagnosis and treatment of left ventricular myocardial injury and abnormal systolic function.Materials and methods1.Research objectThe subjects were 72 MM patients with preserved LVEF(Including first visit and repeat visit patients)in the department of hematology of our hospital from October 2020 to December 2021.According to the echocardiography,divided the patients into two groups:there are 36 cases in ventricular septal thickening group(≥12 mm),and 36 cases in the non-thickening of the group(<12mm),39 cases of normal control group.This study was a prospective clinical trial,which was reviewed and approved by the medical Ethics Committee of our hospital(approval number:2020-study No.088-01).2.Research methodsPart 1:2D-STI assessment of left ventricular myocardial injury in MMCollect general clinical data(sex,age,ECG findings and BNP);echocardiographic indicators:LVEF,left ventricular mass index(LVMI),left atrial volume index(LAVI),etc;2D-STI:layered(endocardial,middle and epicardial)LS,segmental(basal,middle and apical)LS and PSD.One-way analysis of variance or non-parametric test was used to analyze the statistical differences of each indicator between groups,to understand the changes of left ventricular morphology,structure and function,and to judge the synchronization of myocardial mechanical movement.The correlation between LS indicator and BNP in the ventricular septal thickening group was analyzed.Intraclass correlation coefficients(ICC)were used to analyze the inter-observer and intra-observer repeatability of LS correlation coefficients.Difference was statistically significant(P<0.05).Part 2:PSL assessment of MM left ventricular systolic functionLVMW related indicators were obtained by using 2D-STI myocardial work analysis software:Including segmental myocardial work index(WI),global work index(GWI),global constructive work(GCW),global waste work,GWW),global work efficiency(GWE).One-way analysis of variance or non-parametric test was used to analyze the statistical differences of LVMW indicators among groups and the correlation between GLS,PSD and LVMW indicators,and to evaluate the feasibility of using LVMW in systolic dysfunction of MM patients with preserved LVEF.ICC was used to analyze the inter-observer and intra-observer repeatability of LVMW indicators.Difference was statistically significant(P<0.05).ResultsPart 1:(1)The LS of endocardial,middle and epicardial layer in the ventricular septal thickening group were lower than those in the non-thickening group and the normal control group(P<0.05).(2)Compared with the other two groups,the absolute LS in the basal and middle segments of the three layers of myocardium in the septal thickening group was decreased(P<0.05),showing signs of apical preservation.(3)In the septal thickening group,the reduction of LS was mainly in the basal segment of the three layers,and the reduction of LS in the basal segment of the endocardial layer(5/6)was more than that in the basal segment of the middle(3/6)and epicardial layer(2/6).(4)In MM patients with ventricular septum thickening and LVEF preserved,the dispersion of myocardial mechanical motion was larger,and the myocardial contraction synchronization was the worst.(5)Analysis of the correlation between LS and BNP in ventricular septal thickening group:There was a significant positive correlation between GLS-Endo and BNP,LS in the basal segments of the three layers of myocardium and BNP(r=0.429,0.458,0.415,0.365,P=0.016,0.010,0.020,0.044),the correlation between the basal segments of endocardial layer and BNP was higher than other LS indicators.(6)The repeatability test showed high inter-and intraobserver reproducibility and reliability for GLS-Endo,GLS-Mid,GLS-Epi and PSD.Part 2:(1)Groups comparison of segmental myocardial work index(WI):in the septal thickening group the WI of base segment decreased,and the apical/base segment WI and apical/(base segment+middle segment)WI ratios were increased(P<0.05).(2)Compared with the normal control group,GWI,GCW,GWE decreased and GWW increased in the septal thickening group,GCW decreased in the non-thickening group were statistically significant(P<0.05).(3)The correlation analysis showed:GLS was negatively correlated with GWI,GCW,and GWE(r=-0.828,-0.847,-0.407,P=0.000,0.000,0.014).PSD was negatively correlated with GWE(r=-0.694,P=0.000)and positively correlated with GWW(r=0.552,P=0.000).(4)The repeatability test showed high inter-and intraobserver reproducibility and reliability for GWI,GCW,GWW and GWE.Conclusion1、2D-STI can sensibly detect left ventricular myocardial injury in MM patients with thickened ventricular septum and preserved LVEF.LS in the basal segment of endocardial layer is more sensitive to assess regional myocardial injury and systolic dysfunction in the early stage,which can provide reference for early clinical treatment.2、In MM patients with preserved LVEF and thickened ventricular septum,PSD may be a sensitive indicator for the assessment of left ventricular systolic dysfunction.3、LVMW indicators such as basal segment WI and apical/basal segment WI obtained from left ventricular PSL can sensitively detect left ventricular systolic dysfunction in MM patients with preserved LVEF.