Quantitative Assessment Of Mitral Apparatus In Patients With Acute Myocardial Infarction After Percutaneous Coronary Intervention By Real-time Three-dimensional Transthoracic Echocardiography

Objective:to assess the changes of structure and function of the mitral valve before and after percutaneous coronary intervention by Real-time 3-dimensional transthoracic echocardiography. to explore if structure and function of the mitral valve can predict improvement of mitral regurgitation.Methods:sixty-two patients with acute myocardial infarction and mitral regurgitation who were44~72 years,mean(56±12)years, were enrolled to our study, of which all successfully accepted percutaneous coronary intervention(PCI). all patient accepted conventional echocardiography and Real-time Three-dimensional transthoracic echocardiography(RT3D-TTE) at 12 hours before PCI, one week and three month after PCI. Left ventricular end-systolic diameter(LVESD) and Left ventricular end-diastolic diameter(LVEDD) were measured by conventional echocardiography. The imaging was analyzed offline with TomTec 4D LV Volume software to measure Left ventricular end-diastolic volume(LVEDV)Left ventricular end-systolic volume(LVESV) and Left ventricular ejection fraction(LVEF)and with TomTec 4D MV-Assessment software to measure mitral valve structure and function parameters. Compare of conventional echocardiography parameters and mitral valve structure and function parameters between normal control group and Ischemic Mitral Regurgitation(IMR) group. Compare of conventional echocardiography parameters and mitral valve structure and function parameters between different degree of Mitral regurgitation group. Compare of conventional echocardiography parameters and mitral valve structure and function parameters between before and after PCI of Mitral regurgitation group. According to whether improved three months after PCI, Patients with moderate mitral regurgitation were divided into two groups: improvement group and noimprovement group. Compare of conventional echocardiography parameters and mitral valve structure and function parameters between improvement group and no improvement group.Results:(1) Compared with the control group, Anterior-posterior(AP) diameter 、Anterolateral-posteromedial(AL-PM)diameter、Annular circumference(AC)、Commissural diameter(CD) 、 Two-dimensional annular area(AA2D) 、 Three-dimensional annular area(AA3D)、Tenting volume(TV)、Tenting height(TH)、Nonplanarity angle(NPA)of mitral regurgitation group were larger(p<0.05),Annular height(AH)and Maximum annular displacement(ADMax)、Maximum annular displacement velocity(ADVMax)of mitral regurgitation group were smaller( p<0.05),Sphericity index(SPI) of moderate mitral regurgitation group were larger(p<0.05).(2)Compared with the mild mitral regurgitation group, AP、AL-PM、AC、CD、AA2D、AA3D、TV、TH of moderate mitral regurgitation group were larger(p <0.05),AH、ADMax of moderate mitral regurgitation group were smaller(p<0.05).(3)Compared with mitral valve parameters before PCI and one week after PCI, AP、AL-PM、AC、CD、AA2D、AA3D、TV in moderate mitral regurgitation group were discreased three month after PCI(p<0.05),AH was increased(p<0.05).Three month after PCI, twenty patients of moderate mitral regurgitation were improved(effective regurgitant orific area<0.2cm2), twelve patients of moderate mitral regurgitation were no improved. Compared with no improvement group, AP、AL-PM、AC、CD、AA2D、AA3D of improvement group were smaller(p<0.05).(4)IMR was closely correlated with AP、AL-PM、AC、CD. By analysis of ROC curves AP、AL-PM、AC、CD for diagnosing mitral regurgitation had good test effectiveness. Areas under the curve of AP、AL-PM、AC、CD were 0.826、0.808、0.740、0.795.Conclusion:(1) In patients with acute myocardial infarction and mitral regurgitation, the mitralannular was not only presented as the size enlargement but also the flattening of its geometric shape and the decrease of its dynamic.(2) In patients with acute myocardial infarction and moderate mitral regurgitation,three month after PCI, structure and function of the mitral valve improved.(3) In patients with acute myocardial infarction and moderate mitral regurgitation,structure and function parameters of the mitral valve before PCI can predict improvement of mitral regurgitation and provide a reference for the development of clinical programs.