Acute Changes of Mitral Valve Geometry During Interventional Edge-to-edge Repair with the MitraClip System Are Associated with Midterm Outcomes in Patients with Functional Valve Disease: Preliminary Results from a Prospective Single-center Study

Background: Transcatheter mitral valve repair (TMVR) is a treatment option in patients with symptomatic functional or degenerative mitral regurgitation (DMR) at high surgical risk. The acute effect of MitraClip procedure on mitral valve (MV) annular geometry and its relation to functional outcomes is unclear. We sought to assess immediate effect of TMVR on MV annular geometry with 3-dimensional (3D) transesophageal echocardiography and the association of MV diameter reduction with functional response after 6 months.

Methods And Results: Consecutive patients (n = 111; age, 78.3 ± 8.1 years) at high surgical risk (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation], 29.8±21.5%) underwent TMVR. The procedure was completed successfully in 107 (96%) patients with 3D reconstruction of MV annular geometry immediately before and after clip implantation. Only patients with functional mitral regurgitation (n = 71) experienced an acute reduction of anterior-posterior MV diameters (4.0 ± 0.6 and 3.6 ± 0.6 cm; P < 0.0001), MV annulus areas (2D annulus area, 13.9 ± 3.8 and 12.8 ± 3.4 cm(2); P < 0.0001 and 3D annulus area, 14.4 ± 3.9 and 12.9 ± 3.4 cm(2); P < 0.0001), and MV annular geometry (MV sphericity index, 0.9 ± 0.1 and 0.8 ± 0.1; P < 0.0001); the lateral medial MV diameters remained unchanged (4.3 ± 0.7 and 4.4 ± 0.6 cm; P = 0.13). In subjects with DMR, all MV annular geometry-defining values were not significantly altered after TMVR (n = 36; P > 0.05). Acute anterior-posterior diameter reduction was associated with clinical response to TMVR after 6 months of follow-up (cutoff value, ≥ 6.4%; area under the curve, 0.81; P = 0.002; sensitivity, 81.6%; specificity, 81.8%), which was confirmed by additional regression analysis (P = 0.007).

Conclusions: Three-dimensional transesophageal echocardiography enables assessment of acute changes of MV geometry in patients undergoing the MitraClip procedure. Only patients with functional mitral regurgitation experienced significant reduction of MV annular dimensions, which was associated with clinical response to TMVR.