Assessment of biventricular function by three-dimensional speckle tracking echocardiography in secondary mitral regurgitation after repair with the mitraclip system

Background. The goal of this study was to determine the changes of left (LV) and right (RV) ventricular function with three-dimensional speckle-tracking echocardiography (3DSTE) 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. Thirty-two patients with MR undergoing MitraClip were prospectively included. Patients underwent two-dimensional and three-dimensional transthoracic echocardiography before clip implantation and after 6-month follow-up. LV and RV longitudinal strains were obtained by two-dimensional speckle-tracking echocardiography (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 LV 2D global longitudinal strain (p<0.005), 3D global longitudinal strain (p=0.0002), and 3D area strain (p=0.0003). Overall, a significant improvement was also shown in 3D RV ejection fraction (p<0.05) and 3D RV free-wall longitudinal strain (p<0.05). A poor increase in LV strains after clip implantation (p=ns) occurred in patients with pronounced pre-existing RV dysfunction. The areas under the ROC curve (AUC) for LV-RV 3DSTE parameters showed high discriminative values (0.87-0.91) in predicting unfavorable outcome with persistent symptoms (NYHA>II) after the procedure. Conclusions. 3DSTE analysis showed overall LV-RV strain improvement after clip implantation as well as lower post-procedural LV strain 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.