Imaging assessment of the right atrium: anatomy and function

Right Atrial Remodeling and Outcome in Patients with Secondary Tricuspid Regurgitation

BACKGROUND

In patients with secondary tricuspid regurgitation (STR), right atrial remodeling (RAR) is a proven marker of disease progression. However, the prognostic value of RAR, assessed by indexed right atrial volume (RAVi) and reservoir strain (RAS), remains to be clarified. Accordingly, the aim of our study is to investigate the association with outcome of RAR in patients with STR.

METHODS

We enrolled 397 patients (44% men, 72.7 ± 13 years old) with mild to severe STR. Complete two-dimensional and speckle-tracking echocardiography analysis of right atrial and right ventricular (RV) size and function were obtained in all patients. The primary end point was the composite of death from any cause and heart failure hospitalization.

RESULTS

After a median follow-up of 15 months (interquartile range, 6-23), the end point was reached by 158 patients (39%). Patients with RAS <13% and RAVi >48 mL/m2 had significantly lower survival rates compared to patients with RAS ≥13% and RAVi ≤48 mL/m2 (log-rank P < .001). On multivariable analysis, RAS <13% (hazard ratio, 2.11; 95% CI, 1.43-3.11; P < .001) and RAVi > 48 mL/m2 (hazard ratio, 1.49; 95% CI, 1.01-2.18; P = .04) remained associated with the combined end point, even after adjusting for RV free-wall longitudinal strain, significant chronic kidney disease, and New York Heart Association class. Secondary tricuspid regurgitation excess mortality increased exponentially with values of 18.2% and 51.3 mL/m2 for RAS and RAVi, respectively. In nested models, the addition of RAS and RAVi provided incremental prognostic value over clinical, conventional echocardiographic parameters of RV size and function and RV free-wall longitudinal strain.

CONCLUSIONS

In patients with STR, RAR was independently associated with mortality and heart failure hospitalization. Assessment of RAR could improve risk stratification of patients with STR, potentially identifying those who may benefit from optimization of medical therapy and a closer follow-up.

RAS Dataset: A 3D Cardiac LGE-MRI Dataset for Segmentation of Right Atrial Cavity

The current challenge in effectively treating atrial fibrillation (AF) stems from a limited understanding of the intricate structure of the human atria. The objective and quantitative interpretation of the right atrium (RA) in late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) scans relies heavily on its precise segmentation. Leveraging the potential of artificial intelligence (AI) for RA segmentation presents a promising solution. However, the successful implementation of AI in this context necessitates access to a substantial volume of annotated LGE-MRI images for model training. In this paper, we present a comprehensive 3D cardiac dataset comprising 50 high-resolution LGE-MRI scans, each meticulously annotated at the pixel level. The annotation process underwent rigorous standardization through crowdsourcing among a panel of medical experts, ensuring the accuracy and consistency of the annotations. Our dataset represents a significant contribution to the field, providing a valuable resource for advancing RA segmentation methods.

Multimodality Imaging Approach for Planning and Guiding Direct Transcatheter Tricuspid Valve Annuloplasty

Interest in transcatheter treatment of tricuspid regurgitation (TR) has grown significantly in recent years due to increasing evidence correlating TR severity with mortality and to limited availability of surgical options often considered high-risk in these patients. Although edge-to-edge repair is currently the main transcatheter therapeutic strategy, tricuspid valve direct annuloplasty can also be performed safely and effectively to reduce TR and improve heart failure symptoms and quality of life. In the annuloplasty procedure, an adjustable band is implanted around the tricuspid annulus to reduce valvular size and improve TR. Patient selection and careful preoperative imaging, including transthoracic echocardiography, transesophageal echocardiography, and computed tomography, are critical for procedural success and proper device implantation. Compared to edge-to-edge repair, perioperative imaging with transesophageal echocardiography and fluoroscopy is particularly challenging. Alignment and insertion of the anchors are demanding but essential to achieve good results and avoid damaging the surrounding structures. The presence of shadowing artifacts due to cardiac devices makes the acquisition of good-quality images even more challenging. In this review, we discuss the current role of multimodality imaging in planning direct transcatheter tricuspid valve annuloplasty and describe all procedural steps focusing on echocardiographic monitoring.

The Added Value of Advanced Echocardiography for the Morpho-Functional and Prognostic Evaluation of the Right Heart in Dilated Cardiomyopathy: Do Not Forget about the Right Atrium

(1) Introduction and Aims: Right ventricular (RV) remodeling significantly impacts the prognosis of dilated cardiomyopathy (DCM) patients, and right atrial (RA) size and function are still often neglected in DCM patients. Accordingly, our aims were to (i) evaluate right heart subclinical changes and (ii) the prognostic value of RA compared to left atrial (LA) size and function in patients with DCM by advanced echocardiography. (2) Materials and Methods: Sixty-eight patients with DCM (with a mean age of 60 years; 35 men) were evaluated by comprehensive transthoracic echocardiography, compared to 62 age- and sex-matched healthy controls (with a mean age of 61 years; 32 men), and followed up for 12.4 ± 5 months. (3) Results: DCM patients have RV and RA global longitudinal dysfunction by 2DSTE, higher RA minimum volumes and tricuspid annulus areas despite having normal RV volumes, ejection fractions, and RA maximum volumes by 3DE compared to the controls. The RA strain and RV strain are correlated with each other. The RA reservoir strain (with an AUC = 0.769) has an increased value for outcome prediction compared to that of the LA strain. (4) Conclusion: Patients with DCM have RV longitudinal dysfunction and decreased RA function, in the absence of clinical RV involvement or atrial arrhythmias, and the RA strain is associated with an increased risk of hospitalization and cardiac death.

Association of right atrial strain and long-term outcome in severe secondary tricuspid regurgitation

OBJECTIVE

Severe secondary tricuspid regurgitation (STR) causes significant right atrial (RA) volume overload, resulting in structural and functional RA-remodelling. This study evaluated whether patients with severe STR and reduced RA function, as assessed by RA-reservoir-strain (RASr), show lower long-term prognosis.

METHODS

Consecutive patients, from a single centre, with first diagnosis of severe STR and RASr measure available, were included. Extensive echocardiographic analysis comprised measures of cardiac chamber size and function, assessed also by two-dimensional speckle-tracking strain analysis. Primary outcome was all-cause mortality, analysed from inclusion until death or last follow-up. The association of RASr with the outcome was evaluated by Cox regression analysis and Akaike information criterion.

RESULTS

A total of 586 patients with severe STR (age 68±13 years; 52% male) were included. Patients presented with mild right ventricular (RV) dilatation (end-diastolic area 13.8±6.5 cm2/m2) and dysfunction (free-wall strain 16.2±7.2%), and with moderate-to-severe RA dilatation (max area 15.0±5.3 cm2/m2); the median value of RASr was 13%. In the overall population, 10-year overall survival was low (40%, 349 deaths), and was significantly lower in patients with lower RASr (defined by the median value): 36% (195 deaths) for RASr ≤13% compared with 45% (154 deaths) for RASr >13% (log-rank p=0.016). With a median follow-up of 6.6 years, RASr was independently associated with all-cause mortality (HR per 5% RASr increase:0.928; 95% CI 0.864 to 0.996; p=0.038), providing additional value over relevant clinical and echocardiographic covariates (including RA size and RV function/size).

CONCLUSIONS

Patients with severe STR presented with significant RA remodelling, and lower RA function, as measured by RASr, was independently associated with all-cause mortality, potentially improving risk stratification in these patients.

Added value of 3D echocardiography in the diagnosis and prognostication of patients with right ventricular dysfunction

Recent inroads into percutaneous-based options for the treatment of tricuspid valve disease has brought to light how little we know about the behavior of the right ventricle in both health and disease and how incomplete our assessment of right ventricular (RV) physiology and function is using current non-invasive technology, in particular echocardiography. The purpose of this review is to provide an overview of what three-dimensional echocardiography (3DE) can offer currently to enhance RV evaluation and what the future may hold if we continue to improve the 3D evaluation of the right heart.

The Right Ventricle in Pulmonary Hypertension

The right ventricle plays a pivotal role in patients with pulmonary hypertension (PH). Its adaptation to pressure overload determines a patient's functional status as well as survival. In a healthy situation, the right ventricle is part of a low pressure, high compliance system. It is built to accommodate changes in preload, but not very well suited for dealing with pressure overload. In PH, right ventricular (RV) contractility must increase to maintain cardiac output. In other words, the balance between the degree of RV contractility and afterload determines stroke volume. Hypertrophy is one of the major hallmarks of RV adaptation, but it may cause stiffening of the ventricle in addition to intrinsic changes to the RV myocardium. Ventricular filling becomes more difficult for which the right atrium tries to compensate through increased stroke work. Interaction of RV diastolic stiffness and right atrial (RA) function determines RV filling, but also causes vena cava backflow. Assessment of RV and RA function is critical in the evaluation of patient status. In recent guidelines, this is acknowledged by incorporating additional RV parameters in the risk stratification in PH. Several conventional parameters of RV and RA function have been part of risk stratification for many years. Understanding the pathophysiology of RV failure and the interactions with the pulmonary circulation and right atrium requires consideration of the unique RV anatomy. This review will therefore describe normal RV structure and function and changes that occur during adaptation to increased afterload. Consequences of a failing right ventricle and its implications for RA function will be discussed. Subsequently, we will describe RV and RA assessment in clinical practice.

The year 2022 in the European Heart Journal-Cardiovascular Imaging: Part I

The European Heart Journal-Cardiovascular Imaging with its over 10 years existence is an established leading multi-modality cardiovascular imaging journal. Pertinent publications including original research, how-to papers, reviews, consensus documents, and in our journal from 2022 have been highlighted in two reports. Part I focuses on cardiomyopathies, heart failure, valvular heart disease, and congenital heart disease and related emerging techniques and technologies.

The right atrial auricle-Worthy of a new look

INTRODUCTION

The right atrium is the least well studied cardiac chamber. Even less is known about the right atrial appendage (RAA). Recently, the RAA has been shown to be the site of numerous and diverse pathological processes. Furthermore, the RAA can also be the site of origin of atrial fibrillation with obvious implications for ablation procedures. No standard method of transthoracic echocardiography (TTE) for imaging of the RAA can be found in current literature, despite numerous reports for transesophageal echocardiography (TEE).

PURPOSE OF THIS STUDY

The purpose of this study was to determine if a reliable transthoracic window could be found for consistent and reliable imaging of the RAA.

METHOD

30 patients (15 men and 15 women) were included into this study. All patients were placed in the left lateral decubitus position and echocardiography was performed with a Vivid E9 ultrasound system (GE Healthcare). The RAA was visualized by tilting the probe infero-medially from the standard apical four chamber view.

RESULTS

The RAA was visualized in all 30 patients. The RAA followed a consistent upwards and leftwards path anterior to the aortic root.

CONCLUSION

TTE is a valid method of imaging of the RAA.

Right ventricle remodeling after transcatheter tricuspid leaflet repair in patients with functional tricuspid regurgitation: Lessons from the surgical experience

Clinically significant tricuspid regurgitation (TR) is common and associated with excess mortality. At the same time right ventricular (RV) failure is a complex clinical syndrome that results from many causes, but is often associated with long-term prognosis. Whilst results of isolated tricuspid valve (TV) surgery are often unsatisfactory and limited by the prohibitive risk of most patients, the recent development of percutaneous recovery techniques has opened new scenarios. In consideration of the complexity of the mechanisms that lead to right heart failure and RV dysfunction it is important to understand the real advantages that percutaneous TV treatment can offer, more specifically the effect of TR reduction on RV remodeling in the setting of functional tricuspid regurgitation (fTR).