Anatomical predictors of mitral valve area reduction after the implantation of one MitraClip: the spot matter

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction To avoid significant stenosis after edge-to-edge therapy of severe mitral regurgitation (MR) using MitraClip (MC), according to the EVEREST criteria, patients with a mitral valve area (MVA) <4 cm2 should not be treated with this technique. Instead of basing the decision on only one parameter, the anatomical predictors of the reduction percentage should be defined. It is the purpose of this study Methods During the last two years interventions, volume of the MV were acquired by the guiding echocardiographer and, using a dedicated 3-D software MVA before and after clipping were measured and the percentage of reduction calculated. Several baseline anatomical parameters were also evaluated: MV annulus surface and diameters, leaflets surface, percentage of fibrosed/calcified leaflet, tenting volume. The ratio between the two orifices after clipping was also calculated. Results During the study period, 120 patients were evaluated, 69 primary (PMR) and 51 secondary (SMR) mitral regurgitations. The mean reduction of the MVA after one MC was 53.6+/-8.5% with a range of 25-69% and there was no difference when SMR were compared with PMR. Of all the structural parameters that we correlated with the percentage of MVA reduction, the ratio between the two orifices created after the MC implantation was the only one statistically linked. The relation is U-shaped with a maximal MVA reduction for a ratio of the orifices of about 3/5 (figure 1). The correlation was even better for the PMR cases (figure 2). Conclusions The range of MVA reduction following the implantation of one MC is very variable and the only predictor of the percentage of MVA reduction we found was the spot of implantation. Abstract Figure.