Background The purpose of the study was to determine the association between vena contracta area (VCA) and secondary leaflet tethering among mitral valve prolapse (MVP) patients, and thus to further identify and characterize an MVP with pathological leaflet tethering (MVPt+) phenotype. Methods We prospectively evaluated 94 consecutive MVP patients with significant mitral regurgitation (MR) and 20 healthy controls. MVPt+ group was defined as tenting volume index (TVi) > 0.7 ml/m 2. The three-dimensional (3D) geometry of mitral valve apparatus and VCA was measured with dedicated quantification software. Results Of the 94 patients with MVP and significant MR, 31 patients showed a TVi > 0.7 ml/m 2 and entered the MVP with leaflet tethering (MVPt+) group. In stepwise multivariate analysis, only prolapse volume index and TVi was independently associated with 3D VCA. Apart from marked left ventricular and annular enlargement, MVPt+ group presented significantly higher frequency of leaflet flail, greater VCA, elevated plasma levels of NT-proBNP and sPAP. ROC curve revealed that occurrence of leaflet tethering is associated with a VCA ≥0.55 cm 2 in MVP patients. Conclusions Secondary leaflet tethering is a significant mechanism behind severe degenerative mitral regurgitation, resulting an MVPt+ phenotype featuring more advanced morphological and hemodynamical characteristics .

Background Multiple studies illustrated that mitral valve (MV) leaflet presented variations, and there is little known about the posterior mitral leaflet (PML) anatomical variation affecting residual MR in interventional mitral valve edge-to-edge repair (TEER) with the ValveClamp system in patients with degenerative mitral regurgitation (DMR) using three-dimensional transesophageal echocardiography (3D TEE). Method Fifty-five DMR patients treated with TEER were included and performed 3D TEE pre- and post-procedure immediately. 3D TEE images were proceeded to characterize the posterior mitral leaflet anatomy and investigate the relationship between variations and residual mitral regurgitation (MR). Results Variations in PML were found in 16 patients (32%) of this series, including 3 cases (6%) of one scallop, 8 cases (16%) of two scallops, and 5 cases (10%) of four scallops. Residual MR ≥ 2+ were found in 3 patients with variant PML and 8 patients with classical PML post procedures, while other patients were all < 2+. The Chi-square test results showed no correlation between residual MR and PML variants (18.8% vs. 23.5, ᵪ 2 = 0, p = 0.988). Of the 5 patients with 4 scallops, 3 had poor clinical outcomes. Two patients were converted to surgical mitral valve repair and one died 1 month after implantation. Conclusions 3D TEE provides a novel and non-invasive method to characterize and classify PML variations. Variations in PML are relatively common and not associated with residual MR 2+.