Application Of Three-dimensional Echocardiography In The Evaluation Of Valve Annulus Structure And Function In Patients With Mitral Regurgitation

Three-dimensional structure and dynamic changes of valve annulus in patients with mitral regurgitation were evaluated by three-dimensional ultrasound combined with speckle tracking techniqueObjective:The mitral valve(MV)is composed of complex components.Any lesion of any component can lead to mitral valve insufficiency and mitral regurgitation(MR).MR can be divided into primary mitral regurgitation(PMR),secondary mitral regurgitation(secondary mitral regurgitation)and Functional mitral regurgitation(Functional regurgitation)according to its etiation and mechanism.(FMR)and atrial mitral regurgitation(AMR)secondary to atrial arrhythmias.As one of the main components of MV,mitral annulus(MA)is a "saddle-shaped" three-dimensional structure,which will have complex structural changes during the cardiac cycle,including translation,folding and saddle-shaped deepening in various forms of movement.The special non-planar saddle structure of MA and its dynamic changes during the cardiac cycle are very important for maintaining mitral valve function and preventing mitral regurgitation.However,MA is composed of adipose and fibrous tissue,and has no contractility in itself,and its dynamic changes are related to left heart.With the rapid development of three-dimensional echocardiography,it is now possible to carry out detailed quantitative assessment of the geometric structure and dynamic changes of the mitral valve ring,and quantitative assessment parameters of left ventricular and left atrial function can be obtained through speckle tracking technology,which are respectively the global longaxis strain(global longaxis strain,GLS)and Left Atrial strain Reservoir(LASR).At present,there are limited studies on the dynamic changes of MR valve annulus of different etiologies,and the correlation between the dynamic changes of MA and MR,left atrial and left ventricular mechanics is also controversial.The purpose of this study was to explore the static geometric structure changes and dynamic changes of MA in MR of different etiologies,and to explore the correlation between dynamic changes of MA and MR and left ventricle and left atrial function.Methods:In this study,100 MR patients admitted to Fuwai Cardiovascular Hospital of Yunnan Province from March 2020 to February 2021 were prospectively included,and 28 patients with poor image quality that could not be analyzed were excluded.Finally,72 patients were included in the study,including 43 males(59.7%)with an average age of(59.2±12.4)years.According to etiology,MR patients were divided into PMR group(24 cases),FMR group(29 cases)and AMR group(19 cases).The control group consisted of 50 healthy subjects who underwent physical examination in Fuwai Cardiovascular Disease Hospital of Yunnan Province and Fuwai Hospital of Chinese Academy of Sciences in the same period,and 8 patients with poor image quality were excluded.A total of 42 patients were included in the control group,including 16 males(38.1%)with an average age of(40.4±8.1)years.A total of 114 subjects in this study were divided into MR-group(without or only with mild MR)and MR+group(with moderate or severe MR)according to MR degree.MR degree was based on the regurgitant area/Left atrial area ratio(regurgitant area/Left atrial area,RA/LAA)combined with the effective flow outlet area and shrinkage diameter width of multi-parameter comprehensive assessment.Basic vital signs including blood pressure,height,weight,heart rate and other information of MR patients were collected,and clinical complications including hypertension,hyperlipidemia,diabetes,old myocardial infarction,stroke,peripheral vascular disease,atrial fibrillation,other arrhythmias and pulmonary hypertension were recorded.Routine two-dimensional ultrasound measurements included left ventricular end-systolic volume index after body surface area calibration.LVEDVI),left ventricular end-Diastolic volume index(LVEDVI),and left atrial volume index(LATRIAL).LAVI)and left ventricular ejection fraction(LVEF).The MAA and the mitral annular perimeter were measured at four time points:late diastole,early systole,middle systole and late systole.MAP),Antero lateral posteromedial diameter(DALPM),Anteroposterior diameter of the mitral ring(DALPM)DAP),the nonplanarity Angle(NPA),the annular heigh height(AH),and the annular heigh combined width ratio(Annular heigh combined width ratio,annular heigh combined width ratio,AHCWR).The systolic change scores of the above parameters were calculated as dynamic change parameters to intuitively reflect the function of MA,including MAA change score,MAP change score,DALPM change score,DAP change score,NPA change score,AH change score and AHCWR change score.LAsr and left ventricular GLS were obtained by three-and two-dimensional speckle tracking techniques.One-way ANOVA or chi-square test was used to compare the general clinical data,two-dimensional parameters of conventional ultrasound and the fraction of changes in systolic phase of MA parameters in PMR group,FMR group,AMR group and control group.Repeated measure ANOVA was used to compare the dynamic changes of MA in the whole cardiac cycle between the four groups.The correlation between the dynamic change parameters of MA and RA/LAA,LASR and GLS was analyzed by Person correlation.Through univariate and multivariate analysis of the factors related to MR above moderate to severe,the univariate inclusion factors include age,gender,LASR,GLS and MA parameter systole change score,Receiver Operating Characteristic Curve,ROC)to analyze the prediction efficiency of dynamic change parameters of MA to moderate and severe MR.Results:General data comparison:compared with the normal control group,LVEDVI and LVESVI increased in PMR group and FMR group,while there was no difference in AMR group;LAVI increased significantly in PMR,FMR and AMR groups,while LASR and GLS decreased,with the FMR group being the most significant,with statistical significance(P<0.05).The percentage of symptomatic heart failure(NYHA≥Ⅲ)in FMR group was significantly higher than that in PMR and AMR groups.MAA static structure:Compared with the control group,MAA,MAP,DAP and DALPM increased in PMR and FMR groups,MAA and DAP also increased significantly in AMR group,and the increase in PMR group was the most significant,with statistical significance(P<0.05).In the FMR group,the "saddle" shaped structure of the valve annular was significantly flattened,showing that AH decreased significantly in the early and late systolic stages,NPA increased in the total systolic stage,and AHCWR decreased in the whole cardiac cycle compared with the control group,with statistical significance(P<0.05).Compared with the control group,the saddle-shaped structure in the PMR group was flatter in the middle and late systolic stages,and the saddle-shaped structure was relatively retained in the other phases,showing that the NPA in the late systolic stage was higher than that in the control group(P<0.05),but there was no difference in the early and middle systolic stages.AHCWR in the middle and late systolic period was lower than that in the control group(P<0.05),but there was no difference in the early systolic period.There was no significant difference in AH total systole between control group and control group(P>0.05).Compared with the control group,the saddle-shaped structure in the AMR group was flat in the late contraction period,and the saddle-shaped structure was relatively retained in the other phases,showing that NPA was increased in the late contraction period compared with the control group,and AHCWR was decreased in the late contraction period compared with the control group(all P<0.05).There were no statistical differences in NPA and AHCWR in the early and middle contraction period compared with the control group(all P>0.05).There was no significant difference in AH between the control group and the total systolic period(P>0.05).MA dynamic change:In the control group,MA contraction before contraction and saddle-shape deepening were observed,and the DALPM and NPA decreased from late diastole to early contraction,while AH and AHCWR increased,with statistically significant differences(P<0.05).Compared with the control group,the saddle-shape deepening of MA disappeared in PMR,FMR and AMR groups before contraction.DALPM,AH,NPA and AHCWR in late diastolic period and early systolic period were not statistically significant in three groups(P>0.05).In the control group,DALPM continued to decrease during systolic period(P<0.05),while AH and NPA had no significant changes(P>0.05),but AHCWR increased from the middle to the late systolic period(P<0.05),and the overall performance was saddle-shaped deepening from the middle to the late systolic period.Compared with the control group,DALPM,AH,NPA and AHCWR had no significant changes in PMR,FMR and AMR groups from the middle to the late systolic period(P>0.05),and the change fractions of DALPM and NPA in the three groups were lower than those in the control group,indicating that the dynamic changes of systolic period were impaired in all three groups.MR was correlated with valve annular dynamics,GLS and LASR:RA/LAA was moderately correlated with DALPM and NPA systolic changes(r=0.262,P=0.0113 and r=0.425,P<0.0001).There was a moderate correlation between LASR and DALPM and NPA(r=-0.269,P=0.008 and r=-0.324,P=0.001).There was also a moderate correlation between NPA and GLS(r=0.270,P=0.006).Independent influencing factors of moderate to severe MR:Multivariate analysis showed that LASR,DALPM systolic change fraction and NPA systolic change fraction were independent influencing factors of MR+,and ROC analysis showed that DALPM systolic change fraction and NPA systolic change fraction had better predictive effect on MR+,with AUC of 0.641 and 0.637,respectively.Conclusion:There were differences in the structural and functional changes of MR annulus with different etiology.The MA of MR patients with different etiology was more dilated than that of the control group,and the dilation of MR annulus was the most significant in the PMR group.The saddle-shaped structures of different MR groups were damaged to different degrees and flattened,and the saddle-shaped structures of FMR flap ring were the most damaged,while the saddle-shaped three-dimensional structures of PMR and AMR were relatively preserved in the early shrinkage stage.MR patients with different etiology showed impaired dynamic changes,and the contraction of the valve annulus disappeared before contraction,and the dynamic changes of systolic period were also impaired.Left atrial function plays a leading role in MR by mediating valve annulus dynamic changes..Application value of transesophageal three-dimensional echocardiography in transcatheter mitral valve replacementObjective:Mitral rugugitation(MR)is one of the most common valvular diseases.Currently,the main treatment means for mitral regurgitation is surgical valve replacement or repair,but some patients often have high risk of surgery due to age,complications and other reasons.Transcatheter mitral valve replacement(TMVR),which has recently been developed,is an alternative treatment for these patients.TMVR is also an important hot topic in the field of structural cardiac intervention in recent years.Although the development trend and potential of TMVR are improving,it still faces many challenges,among which the high requirements for preoperative evaluation and screening of patients are one of the most prominent problems.Currently,there is little data on TMVR screening,but published data suggest that the rate of TMVR inappropriateness during screening is as high as 60-90%,of which the major factor for inappropriateness in screening is the anatomical inappropriateness of the mitral valve(including valve annulus size and high risk of outflow tract obstruction).Previously,Yunnan Fuwai Cardiovascular Disease Hospital used domestic TMVR valve Mitralfix to successfully perform TMVR surgery for two MR patients with high risk of surgical operations,and the follow-up results were good for half a year,but there was also a high rate of inadequacy(90%)in patient screening.At present,cardiac CT is the gold standard for the measurement of mitral annulus(MA)size before TMVR and the risk assessment of postoperative outflow tract obstruction.However,CT has disadvantages such as contrast agent exposure,motion artifact,and high price and difficulty in repeated examination.The development of three-dimensional transesophageal echocardiography(3DTEE)provides a new imaging method for the preoperative assessment of TMVR,which has the advantages of low cost,non-invasive and convenient,compared with CT.In this study,Mitralfix artificial valve was used as a simulation valve to evaluate the correlation and consistency between 3DTEE and CT measurements of MA in the screening of TMVR patients,and to evaluate the predictive value of TEE parameters on inappropriate screening caused by excessive MA and high risk of LVOT obstruction,so as to explore TEE parameters conducive to the screening of TMVR patients.Methods:In this study,23 patients who were transferred to our hospital for preoperative screening of TMVR due to moderate to severe MR from June 2019 to December 2020 were prospectively included.The basic characteristics and complications of the patients were collected.2DTEE,3DTEE and retrospective whole-period CT images were collected.The 2DTEE images were measured to obtain the interventional septal thickness(IVS)and the interventional mitral valve contra-ventricular septal distance(C-IVS).Left ventricular ejection fraction(LVEF)and Left ventricular end systolic volume were measured offline using QLAP10.0 on 3DTEE images,LVESV)and mitral ring parameters,The two dimensional projection area of mitral annulus(MAA),mitral annulus perimeter(MAP),anteroposterior diameter(ANTEROsterior)are the two dimensional projection areas of mitral annulus(MAA).AP)diameter,anterolateral Posteromedial(AL-PM)diameter,mitror-aortic Angle(M-A)and other parameters.Mimics was used for offline reconstruction and measurement of CT images to obtain the above parameters corresponding to 3DTEE.At the same time,the current two sizes of Mitralfix(inner diameter of 29mm,height of 15mm,inner diameter of 34mm,height of 17mm)were taken as the standard area of new outflow tract after implantation of the artificial valve.The criteria for high risk of LVOT obstruction were new LVOT≤1.75cm2.Finally,the results of CT measurement were used to determine whether the patient had an oversized valve annulus and whether the patient was at high risk of LVOT obstruction.Linear regression and Bland-Altman scatter plot were used to analyze the correlation and consistency between 3DTEE and CT valve annulus measurement parameters.Receiver Operating Characteristic Curve(ROC)was used to analyze the predictive efficacy of 2DTEE and 3DTEE parameters on the screening outcomes determined by CT for large valve annulus and high risk of LVOT obstruction..Results:Of the 23 patients included in the study,3 were excluded from the study due to poor CT image quality,and 20 patients were eventually included in the study,including 14 males(66.7%)with an average age of(69.1±7.8)years.The MAA,MAP and Al-PM diameters measured by 3DTEE were significantly correlated with CT(r=0.86,r=0.89,r=0.83,P=1t;.0001),and there was no systematic bias.The mean and standard deviation of the difference between 3DTEE and CT measurements were-0.23±1.51 cm 2[P=0.52],-2.89±6.86 mm[P=0.08],-1.56±3.69 mm[P=0.05]),There was a moderate correlation between 3DTEE and CT AP diameter measurements(r=0.69,P=.001).The ROC results showed that the 3DTEE MA measurement parameters had good predictive value for the valve annulus size,and the area under the curve(AUC)of MAA,MAP and Al-PM were all 0.97,P=0.002.AUC DAP diameter=0.75.The corresponding thresholds were MAA=11.6 cm2,MAP=122 mm,Al-PM diameter=37 mm and AP diameter=36 mm,respectively.C-IVS and LVESV had a good predictive effect on the high risk of LVET obstruction.C-IVS distance AUC=0.96,threshold=1.7mm,LVESV AUC=0.94,threshold=33ml.Conclusion:The measured values of 3DTEE MA and CT MA showed significant correlation and good consistency.In the screening of TMVR patients for artificial valve MitralFix,the MAA,MAP,Al-PM diameter and AP diameter measured by 3DTEE can better predict the inadequacy of screening caused by too large valve annulus,while C-IVS and LVEDV have good predictive value for the inadequacy of screening caused by high risk of left ventricular outflow tract obstruction.3DTEE has a good application value as a preliminary screening tool for TMVR patients.