Prognostic Impact of Mitral Valve Sphericity Index After Mitral Valve Transcatheter Edge-to-Edge Repair in Functional Mitral Regurgitation.

Background: Changes in mitral valve (MV) morphology during MV transcatheter edge-to-edge repair (MV-TEER) are associated with short-term reduction of mitral regurgitation (MR). However, whether these changes are associated with prognosis remains unclear. Using 3-dimensional transesophageal echocardiography, this study evaluated the impact of MV morphological parameters on the mid-term prognosis of patients with functional MR (FMR).

Methods and results: We analyzed 99 patients with FMR who were treated with MV-TEER. The primary endpoint was a composite of all-cause mortality and hospitalization due to heart failure. Patients were divided into 2 groups based on the post-procedural sphericity index of the mitral valve (SI-MV), which is the ratio of the vertical to horizontal MV diameter. Using receiver operating characteristic curve (ROC) analysis for the primary endpoint, the SI-MV cut-off value was determined to be 0.86. The incidence of the primary endpoint was significantly (log-rank P=0.013) higher among patients with a post-procedural SI-MV >0.86 (circular MV morphology) than among those with post-procedural SI-MV ≤0.86 (elliptical MV morphology). Post-procedural SI-MV >0.86 was an independent determinant of the primary endpoint in multivariate analysis (hazard ratio 2.35; 95% confidence interval 1.25-4.42; P=0.0077).

Conclusions: A larger post-procedural SI-MV is associated with increased mid-term adverse clinical events after MV-TEER in patients with FMR.