Two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of left and right ventricular function after mitraclip implantation in functional mitral regurgitation

Background. Our purpose was to determine the changes of left (LV) and right (RV) ventricular function with two-dimensional (2DSTE) and three-dimensional speckle-tracking echocardiography (3DSTE) after percutaneous mitral valve repair with the MitraClip system (Abbott, Abbott Park, IL) in high-risk surgical patients with severe functional mitral regurgitation (MR). Methods. Patients underwent 2D and 3D transthoracic echocardiography before MitraClip implantation and after 6 months of follow-up. Longitudinal, circumferential, radial strains, and global area strain (GAS) were calculated by 2DSTE and 3DSTE. Data analysis was performed offline. Results. Fifteen patients with moderate-to-severe or severe MR undergoing MitraClip were prospectively included. Device success was achieved in 14 patients. New York Heart Association functional class improved acutely at discharge (from 3.2±0.6 to 2.7±0.5, p<0.005) and continued to improve progressively during follow-up (2.4±0.6, p<0.001). Echocardiography was performed at discharge and at six months. The primary efficacy end point (MR reduction of at least 1.0 grade or reduction of regurgitant orifice area by 0.1 cm2 or LV end-diastolic volume by 10% compared with baseline) was obtained in 11 patients. A significant improvement was shown in 3D LV ejection fraction (27.3±7.2 vs 36.5±10.2%, p<0.005), 3D LV volumes (end-diastolic volume, 139.8±38.4 vs 108.4±39.6mL, p<0.001, end-systolic volume, 109.7±36.8 vs 71.9±38.1mL, p<0.001), 3D left atrial volume (107.4 to 86.5mL, p<0.005), 2D global longitudinal strain (-9.2±2.4 vs -13.8±4.6%, p<0.005), 3D global longitudinal strain (-8.5±2.8 vs -12.2±3.9%, p<0.001), and 3D GAS (-27.8±4.7 vs -31.3±5.2%, p<0.001). A significant improvement was also shown in 3D RV ejection fraction (from 42.2±8.1 to 53.1±7.6%, p<0.005) and 2D global free-wall RV strain (-18.1±4.5 vs -23.3±4.8%, p<0.001). Conclusions. Our results indicate significant improvements of LV and RV function and deformation and clinical parameters 6 months after MitraClip. Compared with 2D LV strain imaging, 3D speckle-tracking echocardiography allowed significantly faster image acquisition and data analysis.