Comprehensive echocardiographic prediction of postprocedural transmitral pressure gradient following transcatheter mitral valve repair.

Iatrogenic mitral stenosis following transcatheter mitral valve repair (TMVR) for relevant mitral regurgitation (MR) is a potential adverse side-effect, known to affect long-term outcome. However, only few determinants of an elevated mean transmitral pressure gradient (TMPG) have been described thus far. We sought to develop an integrative model for the prediction of TMPG following MitraClip (MC) therapy. From 01/2013 to 03/2017, a total of 175 consecutive patients were successfully (MR ≤ 2 + at discharge) treated with a MitraClip implantation at our centre. Of these, a total of 148 patients (54% male, 77.0 ± 6.0 years, 58% with secondary MR) had complete echocardiographic data sets comprising pre- and postinterventional two- and three-dimensional transthoracic (TTE) and transoesophageal (TOE) echocardiograms. Comprehensive studies of predefined parameters were performed. An expert-based prediction model including preprocedural variables (annular ellipticity, mitral valve commissure-to-commissure diameter, preprocedural transmitral pressure gradient and MR aetiology) was set up and validated with a total of 200 bootstrap samples. A nomogram was developed to predict the postprocedural TMPG based on selected echocardiographic variables. Introduction of nomogram-based guiding of MC therapy could help identify patients at risk for postprocedural mitral stenosis, have an influence on preprocedural patient selection and intraprocedural decision making.