Multimodality Imaging of the Anatomy of Tricuspid Valve

Revisiting the anatomy of the right ventricle in the light of knowledge of its development

Controversies continue regarding several aspects of the anatomy of the morphologically right ventricle. There is disagreement as to whether the ventricle should be assessed in bipartite or tripartite fashion, and the number of leaflets to be found in the tricuspid valve. In particular, there is no agreement as to whether a muscular outlet septum is present in the normally constructed heart, nor how many septal components are to be found during normal development. Resolving these issues is of potential significance to those investigating and treating children with congenitally malformed hearts. With all these issues in mind, we have revisited our own experience in investigating the development and morphology of the normal right ventricle. To assess development, we have examined a large number of datasets, prepared by both standard and episcopic microscopy, from human and murine embryos. In terms of gross anatomy, we have compared dissections of normal autopsied hearts with virtual dissections of datasets prepared using computed tomography. Our developmental and postnatal studies, taken together, confirm that the ventricle is best assessed in tripartite fashion, with the three parts representing its inlet, apical trabecular, and outlet components. The ventricular septum, however, has only muscular and membranous components. The muscular part incorporates a small component derived from the muscularised fused proximal outflow cushions, but this part cannot be distinguished from the much larger part that is incorporated within the free-standing muscular infundibular sleeve. We confirm that the tricuspid valve itself has three components, which are located inferiorly, septally, and antero-superiorly.

A Systematic Review of the Design, Method of Implantation and Early Clinical Outcomes of Transcatheter Tricuspid Prostheses

Background

Intervention for tricuspid regurgitation (TR) tends to happen concurrently with and is addressed during mitral valve surgery. Isolated TR interventions, however, are not unusual and are becoming more common. The purpose of this study was to provide a general overview of the transcatheter tricuspid valve implantation (TTVI) devices, taking into account the several design variations, and to unify the implantation technique, existing clinical results, and potential future directions for TR replacement therapy.

Methods

The major databases, namely Pubmed via Medline, Embase, and Cochrane library, were systematically searched from the date of conception until 10 February 2023, in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) standards.

Results

Eleven studies were isolated from a total cohort of 5842 publications. All the transcatheter tricuspid prostheses were circular in design yet categorized into annular tricuspid valve implantation (ATVI) and caval valve implantation (CAVI) groups. Bleeding (25.2%), severe access site and vascular issues requiring intervention (5.8%), device migration or embolization (3.6%), and paravalvular leak (38%) are among the early TTVI-related complications that have been observed. The CAVI group experienced 3 of 28 bleeding cases and 2 of 4 device migration cases.

Conclusions

Following the intervention with a transcatheter tricuspid prosthesis, this review discovered an early favorable outcome and a general improvement in heart failure symptoms. However, there was a lot of variation in their design, implantation technique, and early clinical outcomes. Understanding the design variations, difficulty of implantation and learning from this review's key findings could help with the future development of catheter-based tricuspid valves.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022312142.

Echocardiographic Imaging in Transcatheter Structural Intervention: An AAE Review Paper

Transcatheter structural heart intervention (TSHI) has gained popularity over the past decade as a means of cardiac intervention in patients with prohibitive surgical risks. Following the exponential rise in cases and devices developed over the period, there has been increased focus on developing the role of "structural imagers" amongst cardiologists. This review, as part of a growing initiative to develop the field of interventional echocardiography, aims to highlight the role of echocardiography in myriad TSHIs available within Asia. We first discuss the various echocardiography-based imaging modalities, including 3-dimensional echocardiography, fusion imaging, and intracardiac echocardiography. We then highlight a selected list of structural interventions available in the region-a combination of established interventions alongside novel approaches-describing key anatomic and pathologic characteristics related to the relevant structural heart diseases, before delving into various aspects of echocardiography imaging for each TSHI.

The right ventricle systolic force ratio could predict the severity of the tricuspid regurgitation-RIVIERA ratio

PURPOSE

For assessing the severity of tricuspid regurgitation (TR), there is no gold standard. We developed a parameter, the right ventricular systolic force ratio-RIVIERA, using the continious wave Doppler analysis of TR and pulsed-wave analysis of the right ventricle outflow tract. We hypothesized that the RIVIERA would facilitate the ability to identify severe TR in clinical settings.

MATERIALS AND METHODS

We obtained data from routine transthoracic echocardiograms. All records reporting no or mild TR (n = 732), moderate TR (n = 584), and severe TR (n = 519) TR were reanalyzed to measure vena contracta (VC) width, TR jet area, effective regurgitant orifice (EROA) derived with the proximal isovelocity surface area method, the RIVIERA, and right-sided chamber volumes.

RESULTS

Significant linear trends were demonstrated for right atrial volume index, end-diastolic volume index, RVOT velocity time integral, TR jet area, TR-Vmax, TR-VTI, TR acceleration, VC width, EROA with increasing TR severity. Independent predictors of severe RT included RIVIERA <4.8, VC width ≥0.7 cm, TR jet area > 10 cm² , and EROA ≥0.4 cm² .

CONCLUSION

The RIVIERA is a feasible, effective, and independent predictor of severe TR that enhances established techniques for estimating TR severity. For clinical decision-making and management, accurate measurement and classification of TR severity are essential. Therefore, it should be thought about include the RIVIERA in the integrative method to assessing TR severity.

Tricuspid Valve Geometrical Changes in Patients with Functional Tricuspid Regurgitation: Insights from a CT Scan Analysis Focusing on Commissures

BACKGROUND

Cardiac computed tomography (CT) provides important insights into the geometrical configuration of the tricuspid valve (TV). The purpose of the present study was to assess the geometrical changes of TV in patients with functional tricuspid regurgitation (TR) using novel CT scan parameters and to correlate these findings with echocardiography.

METHODS

This single-center study enrolled 86 patients undergoing cardiac CT and divided them into two groups according to the presence or not of severe TR (43 patients with TR ≥ 3+ and 43 controls). The measurements collected were as follows: TV annulus area and perimeter, septal-lateral and antero-posterior annulus diameters, eccentricity, distance between commissures, segment between the geometrical centroid and commissures, and the angles of commissures.

RESULTS

We found a significant correlation between all annulus measurements and the grade of TR, except in regard to angles. TR ≥ 3+ patients had significantly larger TV annulus area and perimeter, larger septal-lateral, and antero-posterior annulus dimensions, as well as larger commissural distance and centroid-commissural distance. In patients with TR ≥ 3+ and controls, the eccentricity index predicted a circular shape and an oval shape of the annulus, respectively.

CONCLUSIONS

These novel CT variables focusing on commissures increase the anatomical understanding of the TV apparatus and the TV geometrical changes in patients with severe functional TR.

Novel Computed Tomography Variables for Assessing Tricuspid Valve Morphology: Results from the TRIMA (Tricuspid Regurgitation IMAging) Study

BACKGROUND

Computed tomography (CT) is the recommended imaging technique for defining the anatomical suitability for current transcatheter technologies and planning tricuspid valve (TV) intervention. The aim of the Tricuspid Regurgitation IMAging (TRIMA) study was to assess the geometrical characteristics of the TV complex using novel CT parameters.

METHODS

This prospective, single-center study enrolled 22 consecutive patients with severe tricuspid regurgitation, who underwent a cardiac CT study dedicated to the right chambers. The following variables were obtained: annulus area and perimeter, septal-lateral and antero-posterior diameters, tenting height, and anatomical regurgitant orifice area. Moreover, the following novel annular parameters were assessed: distance between commissures, distance between TV centroid and commissures, and angles between centroid and commissures.

RESULTS

A significant phasic variability during the cardiac cycle existed for all variables except for eccentricity, angles, and distance between the postero-septal and antero-posterior commissure and distance between the centroid and antero-posterior commissure. There was a significant relationship between the TV annulus area and novel annular parameters, except for annular angles. Additionally, novel annular variables were found to predict the annulus area.

CONCLUSIONS

These novel additional variables may provide an initial platform from which the complexity of the TV annular morphology can continue to be better understood for further improving transcatheter therapies.

Transcatheter Tricuspid Valve Therapy: From Anatomy to Intervention

Nowadays, severe symptomatic tricuspid regurgitation (TR) affects millions of persons worldwide. However, the benefit of surgical correction of isolated secondary TR remains controversial because of the increased risk of periprocedural mortality and morbidity. In recent years, novel transcatheter tricuspid valve interventions (TTVI) were developed to treat TR, so that TTVI is currently considered in symptomatic, inoperable, anatomically eligible patients. TTVI can be divided into these five domains: edge-to-edge leaflet repair, tricuspid annuloplasty, caval implants, spacer, and total valve replacement. Each transcatheter intervention needs specific imaging protocols for assessing the anatomical feasibility and consequentially predicting the procedural success. This review summarizes the available multimodality imaging tools for screening patients with TR, and identifies anatomical characteristics to choose the best option for the patient.