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/m2. 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/m2 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 cm2 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.
Keywords: 3D transesophageal echocardiography; mitral valve
prolapse; degenerative mitral regurgitation; mitral valve geometry