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 moderate mitral valvular regurgitation before and after percutaneous coronary intervention (PCI) by real-time 3-dimensional transthoracic echocardiography(RT 3D-TTE). Methods Thirty-two patients with acute myocardial infarction(AMI) and moderate mitral regurgitation were enrolled in the study, while 30 healthy subjects were selected as the control group. All patients accepted RT 3D-TTE, the imaging was analyzed offline with TomTec 4D MV-Assessment software. The mitral valve structure and function parameters were measured. All AMI patients were performed RT 3D-TTE at 12 hours before PCI, 1 week and 3 months after PCI. According to whether improved at 3 months after PCI, patients with moderate mitral regurgitation were divided into two groups: improvement group and no improvement group. Results ①Compared with the control group, anterior-posterior(AP) diameter, anterolateral-posteromedial(AL-PM) diameter, annular circumference(AC), commissural diameter(CD), 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), and maximum annular displacement velocity(ADVMax) of mitral regurgitation group were smaller(P<0.05). ②At three months after PCI, 20 patients with moderate mitral regurgitation were improved(effective regurgitant orific area<0.2 cm2), twelve patients with moderate mitral regurgitation were not improved. Compared with mitral valve parameters before PCI and at one week after PCI, AP, AL-PM, AC, CD, AA3D, and TV in improvement group were discreased at three months after PCI(P<0.05), AH was increased (P<0.05). Compared with mitral valve parameters before PCI, mitral valve structure and function parameters after PCI were not improved, compared with those in no improvement group, AP, AL-PM, AC, CD, and AA3D in improvement group were smaller(P<0.05). ③By analysis of ROC curves AP, AL-PM, AC, and CD for diagnosing mitral regurgitation had good test effectiveness. Conclusions In patients with acute myocardial infarction and moderate mitral regurgitation, the mitral annular is not only presented as the size enlargement but also the flattening of its geometric shape and the decrease of its dynamic, while 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. Key words: Echocardiography, real-time three-dimensional; Myocardial infarction; Mitral valve insufficiency