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Background: Recent animal studies have suggested that mitral valve (MV) leaflet remodeling can occur even without significant tethering force and that the postinfarct biological reaction would contribute to the histopathologic changes of the leaflet. We serially evaluated the MV remodeling in patients with anterior and inferior acute myocardial infarction (MI), by using 2- and 3-dimensional transthoracic echocardiography. Additional histopathologic examinations were performed to assess the leaflet pathology., Methods: Sixty consecutive first-onset acute MI (anterior MI, n=30; inferior MI, n=30) patients who underwent successful primary percutaneous coronary intervention were examined (1) before primary percutaneous coronary intervention, (2) at 6-month follow-up, and (3) at follow-up 1 year or later after onset. MV complex geometry including MV leaflet area and thickness was analyzed using dedicated software. Additional histopathologic study compared 18 valves harvested during surgery for ischemic mitral regurgitation (MR)., Results: MV area and thickness incrementally increased during the follow-up period. MV leaflet area significantly increased (anterior MI: 5.59 [5.28-5.98] to 6.54 [6.20-7.26] cm 2 /m 2 , P <0.001; inferior MI: 5.60 [4.76-6.08] to 6.32 [5.90-6.90] cm 2 /m 2 , P <0.001), and leaflet thickness also increased (anterior MI: 1.09 [0.92-1.24] to 1.45 [1.28-1.60] mm/m 2 , P <0.001; inferior MI: 1.15 [1.03-1.25] to 1.44 [1.27-1.59] mm/m 2 , P <0.001); data represent onset versus ≥1 year. Larger annuls, larger tenting, and a reduced leaflet area/annular ratio with smaller coaptation index were observed in patients with persistent ischemic MR compared with those without significant ischemic MR. Histopathologic examinations revealed that MV thickness was significantly greater in chronic ischemic MR compared with acute ischemic MR (1432.6±490.5 versus 628.7±278.7 μm; P =0.001), with increased smooth muscle cells and fibrotic materials., Conclusions: MV leaflet remodeling progressed both in area and thickness after MI. This is the first clinical study to record the longitudinal course of MV leaflet remodeling by serial echocardiography.

Background: Mitral valve prolapse (MVP) is often identified in patients with atrial septal defect (ASD), which occasionally require surgical intervention at the time of ASD closure or even long after the surgery. Ventricular and valvular geometric characteristics in preoperative ASD patients were evaluated by three-dimensional (3D) transesophageal echocardiography., Methods and Results: Mitral valve (MV) complex geometry was quantitatively measured by 3D transesophageal echocardiography in 11 ASD patients (Qp/Qs > 1.5) and 11 controls. The ASD group had a significantly larger indexed prolapse volume and height, with a larger anterior mitral leaflet than controls (0.53 [0.33-0.75] vs 0.057 [0.027-0.11] mL/m 2 , P = .0001; 2.89 [2.13-3.50] vs 0.92 [0.48-1.32] mm/m 2 , P < .0001; 391.3 [346.4-445.1] vs 295.3 (281.9-330.0) mm 2 /m 2 , P = .011, respectively). The right ventricular (RV)-to-left ventricular (LV) end-systolic diameter ratio was larger in the ASD group than in the control group (1.34 [0.96-1.45] vs 0.85 [0.75-0.88], P = .004). The indexed inter-papillary muscle distance (IPMD) was significantly shorter in the ASD group than in the control group (7.77 [6.55-8.24] vs 9.71 [8.64-10.8] mm/m 2 , P = .011). IPMD was significantly correlated with the RV-LV end-systolic diameter ratio (r = -.70, P = .017)., Conclusions: Inward shift of the LV papillary muscle tips due to RV dilation may be a major mechanism of MV prolapse in ASD. At the same time, positive remodeling of the anterior leaflet was observed in the ASD group, which may compensate for the billowing leaflet geometry to maintain effective coaptation. Three-dimensional assessment of the MV apparatus geometry will help to further understand perioperative mitral regurgitation in patients with ASD., (© 2020 Wiley Periodicals, Inc.)

Background: Mitral regurgitation is frequently complicated with atrial fibrillation without apparent organic changes in the leaflet, which occasionally improves after successful radiofrequency catheter ablation. We aimed to evaluate a possible geometric effect of radiofrequency catheter ablation on the mitral valve apparatus., Methods: Forty-three consecutive patients who underwent successful catheter ablation for persistent atrial fibrillation (maintaining sinus rhythm for 6 months after their procedure) were examined by serial real-time 3-dimensional transesophageal echocardiography before and 6 months after catheter ablation. Mitral valve complex geometry was measured using dedicated software for 3-dimensional transesophageal echocardiography., Results: Mitral valve apparatus showed significant reverse remodeling along with left atrial reverse remodeling 6 months after successful catheter ablation (50.5 [39.2-61.0] versus 36.4 [28.9-43.1] mL/m 2 ; P <0.001). The degree of mitral regurgitation decreased in a majority of patients (mitral regurgitation jet area; 1.83 [0.78-3.09] versus 0.77 [0.36-1.47] cm 2 ; P <0.001). Annular area significantly decreased (5.32±0.91 versus 4.73±0.76 cm 2 /m 2 ; P <0.001) in both anterior-posterior and medial-lateral directions. Mitral annular contraction significantly recovered after maintaining sinus rhythm for 6 months (7.51 [4.82-9.62]% versus 9.71 [6.27-13.85]%; P =0.008). There were no significant changes in tenting volume or tenting height (0.46 [0.27-0.89] versus 0.51 [0.32-0.72] mL/m 2 , P =0.744; 2.34 [1.75-3.48] versus 2.76 [1.99-3.08] mm/m 2 , P =0.717). The leaflet surface area also significantly decreased after catheter ablation (5.74 [5.01-6.33] versus 5.19 [4.63-5.64] cm 2 /m 2 ; P <0.001)., Conclusions: Maintaining sinus rhythm after successful catheter ablation promotes reverse remodeling in the mitral valve apparatus and improves so-called atrial functional mitral regurgitation. The positive geometric effect of catheter ablation would be expected to be a possible contributor to better outcomes in patients with atrial fibrillation, in addition to the postprocedural freedom from rhythm disturbance.

Background: Little is known on the mechanism of acute ischemic mitral regurgitation (IMR) caused by sudden-onset left ventricular dysfunction in acute myocardial infarction (MI). We sought to investigate the mitral valve (MV) complex geometry in acute IMR in comparison with chronic IMR by 2-dimensional and 3-dimensional transthoracic echocardiography., Methods and Results: Forty-four first-onset acute MI and 36 previous MI with ≥moderate IMR were examined by 2-dimensional/3-dimensional transthoracic echocardiography. MV morphology was quantitatively analyzed and compared between the 2 groups. Left ventricular end-diastolic volume and left ventricular end-systolic volume were significantly smaller in acute IMR than in chronic IMR (40.8 [33.1-48.3] versus 88.8 [66.5-108.8] mL/m 2 ; P <0.001, 17.8 [17.0-30.1] versus 49.5 [34.2-73.7] mL/m 2 ; P <0.001). MV tenting volume and annular area were significantly smaller in acute IMR compared with chronic IMR (0.98 [0.66-1.68] versus 1.88 [1.16-2.65] cm 3 /m 2 ; P =0.008, 5.17 [4.80-5.86] versus 5.81 [5.47-8.22] cm 2 /m 2 ; P =0.008). Leaflet surface area was significantly smaller in acute IMR than in chronic IMR (5.78 [5.16-6.32] versus 7.56 [6.89-11.32] cm 2 /m 2 ; P <0.001). The ratio of MV leaflet surface area and MV annular area was significantly smaller in acute IMR than in chronic IMR (1.08 [1.01-1.14] versus 1.28 [1.24-1.37]; P =0.001)., Conclusions: Sudden-onset left ventricular dysfunction in acute MI may cause loss of coaptation of the MV even with a relatively mild degree of valve tethering. Compared with previously studied chronic IMR, a smaller leaflet area without leaflet adaptation and a larger hemodynamic burden at the acute onset of MI could result in clinically significant IMR despite relatively small leaflet tethering., (© 2018 American Heart Association, Inc.)

Background: Previously published evidence on ischemic mitral regurgitation (IMR) and its adverse prognosis after myocardial infarction has been based on the severity of IMR in the subacute or chronic period of myocardial infarction. However, the state of IMR can vary from the early stage to the chronic stage as a result of various responses of myocardium after primary percutaneous coronary intervention (PCI)., Methods and Results: Standard echocardiography was serially performed in 546 consecutive patients with first-onset acute myocardial infarction (1) immediately after their arrival (pre-PCI), (2) before discharge (early post-PCI), and (3) 6 to 8 months after PCI (late post-PCI). The course of IMR after primary PCI and the prognostic impact of the IMR in each phase were investigated. IMR was found in 193/546 (35%) patients at the emergency room. In the acute phase after PCI, IMR improved in 63 patients. IMR worsened in 78 patients despite successful PCI. Shorter onset-to-reperfusion time and nontotal occlusion before PCI were the independent predictors of early improvement of IMR. In the chronic phase, IMR improved in 79 patients and worsened in 36 patients. Lower peak creatine kinase-myocardial band was an independent predictor of late improvement of IMR. IMR before PCI worsened 30-day prognosis (P=0.02), and persistent IMR in the chronic phase worsened long-term prognosis (P=0.04) after primary PCI., Conclusions: Degrees of IMR changed in the early and chronic phase after primary PCI for acute myocardial infarction. IMR on arrival and persistent IMR in the chronic phase worsened short-term and long-term prognosis after acute myocardial infarction, respectively., (© 2016 American Heart Association, Inc.)