Background׃ Percutaneous mitral valve repair (pMVR) using Mitraclip device is a established procedure in patients with functional mitral regurgitation (FMR).  Considerable uncertainty remains in clinical Routine about the number of clips needed to treat an individual patient effectively. Aim of the study was to examine the value of 3D-echocardiographic parameters to predict if a single or a multi−clip strategy is needed during pMVR.

Method׃ During pMVR procedure 3D datasets of the mitral valve and the regurgitation jet were obtained by transesophageal echocardiography before and after each clip implantation. For quantification of valve dimensions, the following parameters were derived from a 3D zoom mode dataset (Figure 1):  A-P diameter, as the shortest distance between the highest anterior and posterior points of the mitral annulus; anterolateral-posteromedial (AL-PM) diameter, as the longest diameter of the mitral annulus; MA sphericity index, as the ratio between A-P and AL-PM diameters; annular area; annular height, as the distance between the lowest and the highest points of the mitral annulus; MV tenting volume; anterior and posterior leaflet area; posterior leaflet angle and mitral annular nonplanarity angle , quantifying the ‘‘saddle shape’’ of the mitral annulus. Using multiplanar reconstruction, vena contracta area (VCA_mean) was calculated as a mean value of all cross-sectional areas of the regurgitation jet quantified frame by frame during systole in a 3D color Doppler dataset (Figure 2).  Mitral regurgitation volume (RegVol_VCA) was calculated as the sum of 8-15 products of VCA and the corresponding velocity time integral (VTI) of CW-Doppler signal. Conventional echocardiographic parameters included ejection fraction (EF), left atrial (LA) volume, left ventricular enddiastolic (LVVd) and endsystolic volume (LVVs).

Results׃The study included 65 consecutive patients (age 72 ± 9 years, 47 male) with at least moderate to severe FMR undergoing pMVR. According to the number of clips used during pMVR, the patients were divided into a group with single−clip (Group 1) and a group with multi−clip (group 2) treatment. The results of echocardiographic parameters are presented in Table 1. Patients, who received more than 1 Clip (Group 2), had a larger mitral ring, anterior leaftlet  and vena contracta area compared to group 1. ROC curves for the prediction of mild MR (defined as VCA_mean< 0.2 cm² and RV_VCA <30 ml) after first clip placement were drawn for echocardiographic parameters of valve dimensions and regurgitation severity (Figure 3). VCA_mean and RegVol_VCA derived by 3D color Doppler yielded the higher areas under the ROC curves compared to anatomic parameters of the mitral valve apparatus.

Conclusion: Sorrow echocardiographic evaluation of mitral regurgitation by 3D echocardiography improves planning of clip placement during pMVR.