Secondary Leaflet Tethering in Patients with degenerative mitral
regurgitation and its Association with the Severity of Mitral
Regurgitation
Abstract
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 .