Background and purpose: Significant mitral regurgitation (MR) is frequently associated with coronary artery disease. The precise geometric predictors of significant MR in ischemic cardiomyopathy are not clearly defined. We performed real-time 3D echocardiography (RT3DE) in 48 patients scheduled for infarct exclusion surgery or Dor procedure, 22 of whom had moderate or severe MR (DorMR) and 26 with no or trivial MR (DorNoMR).
Methods: Two orthogonal apical volumetric planes of LV, commissure-commissure (CC) and antero-posterior (AP) planes, were generated during mid-systole. Mitral valve tenting height (MVTht) and area (MVTa) were measured. The degree of leaflet tethering was estimated by the angles between the annular plane and each leaflet (anterior leaflet: Aalpha, posterior leaflet: Palpha).
Results: MVTht (1.11+/-0.14 vs 0.78+/-0.20 cm, P<0.01) and MVTa (1.30+/-0.34 vs 0.87+/-0.27 cm(2), P<0.01) were significantly larger in DorMR compared with DorNoMR. In DorMR, both Aalpha (38+/-6 vs 31+/-7 degrees , P<0.01) and Palpha (60+/-7 vs 41+/-8 degrees , P<0.01) significantly increased more than those in DorNoMR. Multiple logistic regression analysis found Palpha to be the most important geometric predictor of significant MR. MV tenting area was found to be the strongest determinant of MR severity in ischemic cardiomyopathy patients with significant MR by multivariate linear regression analysis.
Conclusions: Detecting significant posterior leaflet tethering, the most important predictor of significant MR, and measuring MV tenting area, the strongest determinant of MR severity, using RT3DE may be helpful in decision making of additive surgical intervention for MR in patients with severe ischemic cardiomyopathy.