Acute effect of MitraClip implantation on mitral valve geometry in patients with functional mitral regurgitation: insights from three-dimensional transoesophageal echocardiography.

AIMS: Our aim was to evaluate the acute effects of transcatheter edge-to-edge mitral valve repair using the MitraClip device on mitral valve geometry in patients with functional mitral regurgitation (FMR).

METHODS AND RESULTS: Forty-two patients (age 73 years [IQ range 66.1-78.0], 55% men, 62% ischaemic FMR) with moderate-to-severe and severe FMR treated with the MitraClip were included. Three-dimensional transoesophageal echocardiography was performed prior to and immediately after MitraClip implantation. Acute changes of mitral annular and leaflet geometry were assessed with dedicated mitral modelling software. FMR less than moderate grade was achieved in 36 (86%) patients. After MitraClip implantation, the mitral annulus became more elliptical (ellipticity from 122±17% to 129±18%; p=0.04) with a non-significant reduction in anteroposterior diameter (33±6 to 32±5 mm, p=0.08). The coaptation area increased from 350 mm2 (IQ range 289-493 mm2) to 434 mm2 (IQ range 328-523 mm2, p=0.008). In particular, a larger part of the anterior mitral leaflet was included in the coaptation, leaving a smaller exposed anterior leaflet length of the A2 segment (from 27±6 mm to 25±5 mm, p<0.05) while the exposed length of the posterior leaflet (P2 level) remained unchanged (12±4 mm pre- vs. 13±4 mm post-repair, p=0.15). There was no change in total leaflet area (1,811±582 mm2 pre- vs. 1,870±506 mm2 post-repair, p=0.18). Annular height to intercommissural width ratio and tenting volume remained unchanged, suggesting no increase in leaflet stress.

CONCLUSIONS: The MitraClip device affects MV geometry in FMR patients by increasing mitral annular ellipticity and coaptation area.