Effects of Mitral Annulus Remodeling Following MitraClip Procedure on Reduction of Functional Mitral Regurgitation

Abstract

Introduction and objectives: The percutaneous mitral valve repair procedure (MitraClip) appears to reduce mitral annulus diameter in patients with functional mitral regurgitation, but the relationship between this and regurgitation severity has not been demonstrated. The aim of this study was to determine the effect of mitral annulus remodeling on the reduction of mitral regurgitation in patients with functional etiology.

Methods: The study included all patients with functional mitral regurgitation treated with MitraClip at our hospital until January 2015. Echocardiogram (iE33 model, Philips) was performed in all patients immediately after device positioning. Changes in the mitral annulus correlated with mitral regurgitation severity, as assessed using the effective regurgitant orifice area.

Results: The study included 23 patients (age, 65±14 years; 74% men; left ventricular ejection fraction, 31%±13%; systolic pulmonary artery pressure, 47±10 mmHg). After the procedure, the regurgitant orifice area decreased by 0.30 cm²±0.04 cm² (P<.0005), from a baseline of 0.49 cm²±0.09 cm². Anteroposterior diameter decreased by 3.14 mm±1.01 mm (P<.0005) from a baseline of 28.27 mm±4.9 mm, with no changes in the intercommissural diameter (0.50 mm±0.91 mm vs 40.68 mm±4.7 mm; P=.26). A significant association was seen between anteroposterior diameter reduction and regurgitant orifice area reduction (r=.49; P=.020).

Conclusions: In patients with functional mitral regurgitation, the MitraClip device produces an immediate reduction in the anteroposterior diameter. This remodeling may be related to the reduction in mitral regurgitation.

Keywords: Anillo mitral; Ecocardiografía tridimensional; Insuficiencia mitral; MitraClip; Mitral annulus; Mitral regurgitation; Three-dimensional echocardiography.