Mitral annulus morphometry in degenerative mitral regurgitation phenotypes.

OBJECTIVES: Degenerative mitral regurgitation (DMR) is classified into different phenotypes based on the extent of leaflet degeneration. Our aim is to demonstrate that phenotype complexity predicts the extent of structural abnormalities of mitral annulus (MA). METHODS AND RESULTS: Seventy-five patients with DMR and severe valve regurgitation and 23 patients with normal mitral valve were studied using 3D transesophageal echocardiography. Classification of DMR was done by allocating each 3D echocardiography result under five categories: fibroelastic deficiency (FED), FED+, forme fruste, Barlow's disease Mitral annular disjunction (BD MAD)- or BD MAD+. MA was reconstructed in early systole and in end systole. We tested for a trend toward enlargement and flattening of MA in end systole and for a difference in MA dynamics from early systole to end systole with a worsening of DMR phenotype, in the whole spectrum of subjects ranging from controls to BD MAD+. A significant trend was observed toward larger anteroposterior diameter, intercommissural diameter, annulus circumference, and annulus area (P < .001). A reduction was found in annulus height to commissural width ratio (P = .003): This indicates a progressive MA flattening. Prolapse height and prolapse volume tended to be larger (P < .001). CONCLUSION: Based on the extent of leaflet degeneration, DMR is classified into different phenotypes. As the disease progresses, a related increase in MA size is found, with rounder annular shape, loss of saddle shape, and increase in height and volume of leaflet prolapse. The most pronounced alterations are found in BD MAD+.

Mitral valve annuloplasty and papillary muscle relocation oriented by 3-dimensional transesophageal echocardiography for severe functional mitral regurgitation.

OBJECTIVE: The study of the mitral valve apparatus and its modifications during functional mitral regurgitation (FMR) is better revealed by 3-dimensional (3D) transesophageal echocardiography (TOE). To plan mitral valve repair by annuloplasty and papillary muscle (PPM) relocation, we proposed a valve repair procedure oriented by the new main features obtained by real-time 3D TOE reconstruction of the mitral valve apparatus. METHODS: Since January 2008, 25 patients with severe FMR before mitral valve repair were examined. Mean coaptation depth and mean tenting area were 1.3 ± 0.2 cm and 3.2 ± 0.5 cm(2), respectively. Intraoperative 2D and 3D TOE were performed, followed by a 3D offline reconstruction of the mitral valve apparatus. A schematic mitral valve apparatus model was obtained. A geometric model like a truncated cone was traced in according to the preoperative measurements. The size of the prosthetic ring was selected preoperatively according to the anterior leaflet surface. The expected truncated cone after annuloplasty was retraced. A conventional normal coaptation depth about 0.6 cm was used to detect the new position of the PPM tips. RESULTS: Offline reconstruction of the mitral valve apparatus and respective truncated cone were feasible in all patients. The expected position of the PPM tips desirable to reach a normal tenting area with a coaptation depth 0.6 cm or less was obtained in all patients. After surgery, all parameters were calculated and no statistically significant difference was found compared with the expected data. CONCLUSIONS: PPM relocation plus ring annuloplasty reduce mitral valve tenting and may improve mitral valve repair results for patients with severe FMR. This technique may be easily and precisely guided by preoperative offline 3D echocardiographic mitral valve reconstruction.