The role of three dimensional transesophageal echocardiography in predicting the effect of cardiac resynchronization therapy on mitral regurgitation in patients with low ejection fraction heart failure

Purpose Cardiac resynchronization therapy (CRT) positively affects the improvement of functional mitral regurgitation (MR) in patients with heart failure with reduced ejection fraction (HFrEF). However, geometric changes in the mitral valve apparatus, subvalvular structures and their contribution to improving mitral regurgitation after CRT have not been clearly defined. Our study aimed to evaluate the geometric parameters of mitral valve apparatus measured with three‐dimensional (3D) transesophageal echocardiography (TEE) before CRT implantation and to determine the parameters predicting the improvement of MR after CRT. Methods In this prospective study, we included thirty patients with moderate or severe MR and HFrEF planned for CRT implantation who had an indication for TEE. Before CRT implantation, effective regurgitant orifice (ERO) and regurgitant volume (RV) measurements were performed. Detailed quantitative measurements of the mitral valve were done from recorded images by 3D TEE. ERO and RV measurements were repeated to evaluate MR at the end of the third month. Results There were no significant changes in left ventricular EF and left ventricular diameters at third‐month follow‐up, whereas ERO and RV values were decreased. The posterior leaflet angle was higher in the non‐responder group than the responder group (28.93 ± 8.41 vs 41.25 ± 10.90, p = 0.006). The posterior leaflet angle was an independent predictor of decreased RV and ERO. Conclusion Among HFrEF patients with moderate or severe functional MR who underwent CRT implantation had a lower posterior leaflet angle, which was measured by 3D TEE, in the patient group whose MR improved after CRT.