Mid-term repair durability after MitraClip implantation in patients with functional mitral regurgitation

BACKGROUND: The aim of this study was to identify variables that are associated with the durability of percutaneous repair of secondary mitral regurgitation at 6-month follow-up. METHODS AND RESULTS: Thirty-five consecutive patients with functional mitral regurgitation scheduled for MitraClip implant were enrolled. Left ventricular (LV) volumes and function and mitral valve characteristics were assessed before and immediately after MitraClip implantation using three-dimensional transesophageal echocardiography. Five patients with an unsuccessful procedure were excluded. The other patients were subdivided according to repair durability: group 1 with a durable repair (19 patients, 65%) and group 2 with significant mitral regurgitation recurrence (11 patients, 35%). At baseline, group 1 patients had smaller and more elliptical mitral valve annulus (1055 ± 241 vs. 1273 ± 359 mm, P = 0.02 and 125 ± 11 vs. 117 ± 16%, P = 0.02), a smaller left atrial volume (54.1 ± 26 vs. 71.5 ± 20 ml, P = 0.005) and lower systolic pulmonary artery pressure (38 ± 11 vs. 49 ± 12 mmHg, P = 0.03). Baseline LV end systolic volume had a linear correlation with the 3D annulus area (P = 0.048) and an inverse correlation with annulus ellipticity (P = 0.021). Group 1 patients showed an increase in annulus ellipticity after MitraClip (125 ± 17 vs. 141 ± 23%, P = 0.014). CONCLUSION: Percutaneous mitral valve repair leads to a significant and stable mitral regurgitation reduction in a large number of patients. Annulus dimensions and remodeling as well as left atrial area and pulmonary hypertension seem to be associated with durability of the procedure.