Discussion
The present study conducted provides new information on the 3D MV
geometry focusing on leaflet tethering and its association with 3D VCA,
with a large population of MVP patients.
The principal finding of the present study is that, secondary leaflet
tethering is a significant mechanism behind severe degenerative mitral
regurgitation, resulting an MVPt+ phenotype featuring more advanced
morphological and hemodynamical characteristics.
In detail, (1) we corroborated that TVi and PVi, rather than annular
dimension, were the major independent determinants of 3D VCA in MVP
patients with significant MR (2) we carefully defined a cutoff value to
characterize the occurrence of pathological leaflet tethering in MVP
patients (MVPt+ group) (3) apart from marked LV and annular enlargement,
MVPt+ group presented significantly greater 3D VCA, elevated plasma
levels of NT-proBNP and sPAP (4) Occurrence of leaflet tethering is
associated with a 3D VCA ≥ 0.55 cm2 in MVP patients
and it could be a specific marker for severe MR (Figure 4). Our findings
may bring new insights into risk stratification and surgical decision
making to MVP patients.