Three-Dimensional Echocardiographic Assessment of Mitral Annular Physiology in Patients With Degenerative Mitral Valve Regurgitation Undergoing Surgical Repair: Comparison between Early- and Late-Stage Severe Mitral Regurgitation

Abstract

Background: Ventricular-annular decoupling is thought to exist in all degenerative myxomatous mitral valve (MV) diseases. However, the annular physiology of degenerative MV disease may differ when severe mitral regurgitation (MR) presents at different stages. The aim of this study was to assess differences in mitral annular physiology and surgical effects between early- and late-stage severe MR.

Methods: Three-dimensional (3D) transesophageal echocardiography was performed before and after MV surgery in 74 patients with degenerative MV disease, including 57 with early-stage severe MR (without left ventricular remodeling) and 17 with late-stage MR (with left ventricular remodeling). A control group comprised 46 patients without MV disease. Novel 3D MV software was used to evaluate mitral annular dynamics. The degree of annular saddle shape was calculated as the ratio of annular height (AH) to lateromedial diameter (LM). Ventricular-annular decoupling was defined as insufficient systolic AH/LM compared with the control group.

Results: Prebypass 3D measurements demonstrated that systolic AH/LM in the early-stage group (0.19 ± 0.04) was similar to that in the control group (0.21 ± 0.05; P = .101), while systolic AH/LM in the late-stage group (0.17 ± 0.04) was lower than that in the control group (P = .011). Postbypass comparison showed saddle shape accentuation in the early-stage group (0.20 ± 0.04), similar to that in the control group (P = .3127); the mitral annulus remained flat in the late-stage group (0.17 ± 0.03; P = .004).

Conclusions: Ventricular-annular decoupling, present in the late-stage group, was absent in the early-stage group. MV repair surgery did not disrupt mitral annular saddle shape in the early-stage group; however, it failed to correct annular dysfunction in the late-stage group. Sequential 3D transesophageal echocardiographic analysis provides comprehensive mitral annular evaluation beyond conventional two-dimensional parameters for determining stages of severe MR.

Keywords: 3D echocardiography; Degenerative mitral valve disease; Mitral regurgitation; Mitral valve annulus; Saddle shape.