Leaflet Area as a Determinant of Tricuspid Regurgitation Severity in Patients With Pulmonary Hypertension

Abstract

Background Tricuspid regurgitation (TR) is a risk factor for mortality in pulmonary hypertension (PH). TR severity varies among patients with comparable degrees of PH and right ventricular (RV) remodeling. The contribution of leaflet adaptation to the pathophysiology of TR has yet to be examined. We hypothesized that tricuspid leaflet area (TLA) is increased in PH, and that its size relative to RV remodeling determines TR severity. Methods and Results A prospective cohort of 255 patients with PH from pre- and post-capillary etiologies was assembled from two centers. Patients underwent a 3-D echocardiogram focused on the tricuspid apparatus. TLA was measured with the Omni custom software package. Compared with normal controls, PH patients had a twofold increase in RV volumes, 62% increase in annulus area, and 49% increase in TLA. Those with severe TR demonstrated inadequate increase in TLA relative to the closure area, such that the ratio of TLA-to-closure area <1.78 was highly predictive of severe TR (odds ratio 68.7; 95% CI 16.2, 292.7). The median vena contracta width was 8.5 mm in the group with small TLA and large closure area as opposed to 4.8 mm in the group with large TLA and large closure area. Conclusions TLA plays a significant role in determining which patients with PH develop severe functional TR. The ratio of TLA-to-closure area, reflecting the balance between leaflet adaptation vs. annular dilation and tethering forces, is an indicator of TR severity that may identify which patients stand to benefit from leaflet augmentation during tricuspid valve repair.

Echocardiographic evaluation of the right ventricular dimension and systolic function in dogs with pulmonary hypertension

“…This is in line with the literature on humans, where RV size and remodeling in patients with PH is mostly influenced by TR severity . In patients with PH, TR is mainly caused by tricuspid annulus dilation and papillary muscle displacement secondary to RV remodeling . The development of TR leads to RV volume overload and presumably triggers a cycle of progressive annular dilation, RV remodeling, and worsening of TR .…”

Functional Tricuspid Regurgitation Caused by Chronic Atrial Fibrillation

“…18 The TV tenting volume can be measured with 3D echocardiography and has been shown to be a major determinant of residual FTR after surgical annuloplasty. 22 In addition, factors leading to leaflet tethering are reportedly associated with RV remodeling such as spherical shape 9 and papillary muscle displacement.…”

Atrial functional tricuspid regurgitation: An underappreciated cause of secondary tricuspid regurgitation

“…In the past few years, the phenomenon of adaptive leaflet growth (valvulogenesis) has been shown to be an important disease modifier that decreases valvular regurgitation by increasing leaflet coverage area relative to closing area. Adaptive leaflet growth has been demonstrated in ventricular functional TR, ischemic mitral regurgitation, and AF‐mitral regurgitation . Additional research is needed to determine to what extent it influences TR severity in AF‐TR.…”