Value of conventional and speckle tracking echocardiography in the assessment of biventricular function in secondary mitral regurgitation after repair with the MitraClip system

Background. The aim of this study was to determine the comparative value of conventional echocardiography and two-dimensional (2STE) and three-dimensional speckle-tracking echocardiography (3DSTE) in the assessment of left (LV) and right (RV) ventricular function after percutaneous mitral valve repair with the MitraClip system in high-risk surgical patients with moderate-to-severe or severe secondary mitral regurgitation (MR). Methods. Twenty-nine patients underwent two-dimensional transthoracic echocardiography before mitral clip implantation and after 6-month follow-up. LV and RV longitudinal strains were obtained by 2DSTE and 3DSTE. LV circumferential, radial, and area strains were calculated by 3DSTE. Data analysis was performed offline. Results. At 6-month follow-up a significant improvement was shown in 2D LV ejection fraction (p<0.005), 2D LV end-diastolic volumes (p<0.005), 2D LV end-systolic volumes (p<0.001), 2D left atrial volume (p<0.005), 2D global longitudinal strain (p<0.005), 3D global longitudinal strain (p<0.001), and 3D global area strain (p<0.001). Overall, a significant improvement was also shown in RV fractional area change (p<0.05), tricuspid annular plane systolic excursion -TAPSE- (p<0.05), 2D global free-wall RV strain (p<0.001), and 3D global free-wall RV strain (p<0.001). A poor increase in LV strains and decrease in LV volumes after clip implantation (p=ns) occurred in patients with pronounced pre-existing RV dysfunction. The areas under the ROC curve (AUC) showed satisfactory discriminative values both for conventional parameters (0.72-0.81) and 2D-3DSTE parameters (0.86-0.91) in predicting unfavorable outcome with persistent symptoms (NYHA>II) after the procedure. Conclusions. Our data showed overall LV-RV performance indices improvement after clip implantation as well as lower post-procedural LV echocardiographic values in patients with worse pre-existing RV function. These findings could help in guiding MR treatment strategies suggesting different therapies in the presence of marked RV impairment or viceversa anticipating the procedure in case of evolving RV dysfunction.