Geometry of Tricuspid Valve Apparatus in Patients with Mitral Regurgitation due to Fibroelastic Deficiency versus Barlow Disease: A Real-Time Three-dimensional Transesophageal Echocardiography Study

Abstract

Tricuspid valve (TV) geometry gained attention when the prognostic significance of tricuspid regurgitation (TR) was determined. However, the TV geometric characteristics in Barlow disease (BD) have not been elucidated. This study aimed to clarify the difference in TV morphology between BD and fibroelastic deficiency (FED) and the effect of its geometry on residual TR after tricuspid annuloplasty (TAP) using three-dimensional (3D) transesophageal echocardiography. Based on the mitral valve (MV) morphology defined by 3D transesophageal echocardiography, 106 patients with degenerative MV disease were classified into BD (n=42) and FED (n=64). Three-dimensional images of the TV were analyzed using a quantification software to compare the geometrical parameters. Among them, 35 patients (17 with BD and 18 with FED) underwent concomitant TAP during MV surgery, and the residual TR after TAP was evaluated within 1month. TV annulus area, billowing height, and billowing volume were greater in BD than in FED (10.8±2.9 vs 9.2±2.4cm2, 4.6±1.6 vs 2.3±1.1mm, and 1.3±0.8 vs 0.3±0.3mL; all P<.01). In contrast, TV tenting height and tenting volume were smaller in BD than in FED (2.6±1.5 vs 4.4±2.4mm and 0.3±0.4 vs 0.9±1.0mL; both P<.01). These morphologic differences in TV were similar to those in MV. There was a strong correlation between MV billowing volume and TV billowing volumes (R=0.83, P<.01). The prevalence of significant residual TR after TAP was greater in BD than in FED (35% vs 0%, P<.01). Moderate correlations between TV billowing height and volume and residual TR after TAP were observed (R=0.47 and 0.49, respectively, both P<.01). Patients with BD exhibited larger TV annulus area and billowing than FED patients. These results suggest that degenerative changes in the TV apparatus in BD patients are similar to that seen in the MV apparatus. These findings should be taken into consideration when a TV surgery is required.