Study of different patterns of left ventricular remodeling in patients with functional mitral regurgitation and coronary artery disease

Objectives: Functional mitral regurgitation (FMR) is due to LV remodeling despite a structurally normal valve. The choice of surgical approach requires detailed understanding of individual underlying mechanisms. Recently, leaflets tethering has been addressed as amajor factor of ischemic MR. Our purpose was to assess the relationship between FMR and global or regional LV remodeling.

Methods: We studied two groups of patients with FMR: (1) 65 with coronary artery disease and MR; (2) 16 with idiopathic dilated cardiomyopathy. Global and regional LV remodeling patterns were assessed by sphericity index and by displacement of anterior and posterior papillary muscles, respectively. The degree of MR was assessed semiquantitatively (1+ to 4+) and quantitatively by 3D Doppler as the volume of regurgitant jets. Mitral annulus geometry was evaluated by diameters, areas and percentual shortening.

Results: No significant differences in LV remodeling patterns, sphericity index, and displacement of papillary muscles were found between group 1 and 2. MR degree was higher in group 1. Annulus geometry and function was impaired in group 2. Two patterns of LV remodeling could be clearly identified in group 1: a) 49 patients (79%) with global LV enlargement; b) 13 (21%) with regional LV dilation, mostly due to posterior infarction, with impaired leaflet tethering.

Conclusions: These findings suggest that global LV remodeling plays a major role in ischemic FMR than the altered tethering mechanism. The recognition of the remodeling pattern in each patient may have a major impact on functional outcome of surgery for ischemic FMR.