Computed tomography for transcatheter tricuspid valve development

Abstract

Background: Patients with severe symptomatic tricuspid regurgitation (TR) are often deemed ineligible for surgical valve repair due to comorbidities. In this setting, transcatheter tricuspid valve replacement (TTVR) is undergoing development, but delivery technique and prosthesis design have yet to be optimized. We sought to assess the challenges of TTVR and the determinants of venous route using computed tomography (CT) analysis.

Methods and results: A total of 195 end-diastolic cardiac CT performed prior to surgical correction of a severe TR (n = 38), transcatheter aortic valve replacement (n = 89), or left atrial appendage closure (n = 68) were analyzed. Patients with TR (n = 68; 19 primary and 49 secondary) were compared with patients without (n = 127). Continuous variables with normal and non-normal distributions were compared using Student t test or Mann-Whitney test respectively. The angle from the tricuspid annulus (TA) to the inferior vena cava was tighter (mean = 101 ± 18°) with a broader range of value (44° to 164°) than to the superior vena cava (mean = 143 ± 9°). Patients with TR had rounder TA (eccentricity index of 0.88 ± 0.08, p < 0.001), with a larger area (p < 0.0001), and septolateral (45.3 ± 8.0 mm, p < 0.0001) and anteroposterior (44.4 ± 7.4 mm, p < 0.0001) diameters than patients without. The distances from the TA to the coronary sinus, the right ventricular outflow tract, and the moderator band were respectively 11.4 ± 3.8 mm, 17.2 ± 3.4 mm, and 31.0 ± 6.7 mm, without differences between groups.

Conclusion: The transjugular access for TTVR is straighter and more reproducible than the transfemoral access. Prosthesis development may be challenged by the close position of the coronary sinus, the presence of a moderator band, and the large TA size of patients with severe TR.

Key points: • The tricuspid annulus is larger in patients with severe tricuspid regurgitation, confirming existing data. • The coronary sinus ostium is close to the tricuspid annulus, requiring a prosthesis with a short atrial length. • The transjugular venous route may be the preferred access to the tricuspid annulus, straighter with less inter-individual variations than the transfemoral route.

Keywords: Heart valve prosthesis implantation; Radiology, interventional; Tomography, X-ray computed; Tricuspid regurgitation.