Many hands make light work. Echocardiography and computed tomography results from the Tricuspid Regurgitation IMAging (TRIMA) study
Authors: Cammalleri V , Carpenito M , Nobile E , De Filippis A , Bono M C , Mega S , Nusca A , Cocco N , Vitez L , De Stefano D , Quattrocchi C C , Ussia G P , Grigioni F 
Published: October 2022

Abstract

Background
Anatomic knowledge of the tricuspid valve (TV) is the first step in the diagnostic algorithm of patients with tricuspid regurgitation (TR), who are candidates for transcatheter tricuspid valve intervention (TTVI). Currently, echocardiography and computed tomography (CT) are available instruments to study the TV anatomy, guide the decision-making process and support the development of novel transcatheter therapies.

Purpose
The Tricuspid Regurgitation IMAging (TRIMA) study aimed to correlate CT parameters to commonly used echocardiographic variables.

Methods
This prospective, single-center study enrolled 22 consecutive patients with TR equal to or greater than severe (≥3+). All patients underwent transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE) and cardiac CT study, in order to obtain anatomical dimensions of the tricuspid annulus and quantification of right-chambers remodeling and function. Novel CT scan measurements were analyzed. Correlation between measurements on echocardiography and CT imaging was assessed.

Results
Severe TR (3+) was present in 27.4% patients, massive (4+) in 4.8% and torrential (5+) in 3.2%. The mean right ventricle (RV) length, RV mid diameter, and right atrium area were 60.81±9.11 mm, 41.27±7.67 mm and 31.72±9.66 cm2, respectively. Tricuspid annular plane excursion, fractional area change, longitudinal myocardial velocity (S') were 16.09±3.25 mm, 33.36±9.47% and 9.18±1.94 cm/sec, respectively. The annular dimensions obtained by CT scan were generally observed to reduce from diastole to systole, except for eccentricity, angles and distance between the postero-septal and antero-posterior commissure and distance between centroid and antero-posterior commissure. A Kruskal-Wallis test showed a stepwise increase in the tricuspid anatomical regurgitant orifice area (AROA) values by CT across the expanded TR grades by TEE, χ2(2)=6,466, p=0.039. Using the Pearson correlation coefficient, we found a relationship between the AROA and TR grade (r=0.593; p&lt;0.004), as well as ARO-perimeter and TR grade (r=0.470; p&lt;0.027). Additionally, a significant correlation was found between septal lateral annulus diameter obtained by TEE and CT (r=0.637; p=0.001). Anyway, no correlations were found between novel CT variables and TR grade or RV function assessed by echocardiogram, as well as between CT systo-diastolic annulus variability and RV function.

Conclusions
Standard echocardiographic study provide invaluable information about the anatomy and function of the right-chambers, as well as an accurate grade of TR. Conventional and novel variables derived by CT scan may step up the anatomical assessment of the complex morphology of the TV apparatus, thanks to the high spatial resolution of the technique. Therefore, an integrated multimodality assessment is the key point of the screening process of TR candidates for TTVI.

Funding Acknowledgement
Type of funding sources: None.