Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Prognostic value of cardiac CT-derived RV dysfunction in lung transplantation candidates: A single-center retrospective study

BACKGROUND

There are no specific criteria for listing and prioritizing lung transplantation (LTx) candidates based on the severity of right ventricular (RV) dysfunction. We evaluated the prognostic value of cardiac CT-derived right ventricular ejection fraction (RVEF) in LTx candidates.

METHODS

This retrospective study included patients who were listed for LTx and underwent cardiac computed tomography (CT) between September 2019 and December 2023. Patients were categorized into 3 groups based on CT-derived RVEF and survival analyses were performed among these groups: normal RVEF (≥45%), mild-to-moderate RV dysfunction (25%-45%), and severe RV dysfunction (<25%).

RESULTS

In the 203 patients (median age, 61 years [interquartile range [IQR], 54-64]), the most common indication for LTx was interstitial lung disease (79.3%). Patients were followed for a median duration of 297 days (IQR, 140-632), and the 1-year survival rates were 85.2% for those with normal RV, 69.3% for those with mild-to-moderate RV dysfunction, and 55.6% for those with severe RV dysfunction (p < 0.001). Severe RV dysfunction (hazard ratio [HR] 6.72, p = 0.020), age (HR 1.1, p = 0.010), and 6-minute walking distance (HR 0.62, p = 0.010) were associated with an increased risk of 1-year mortality.

CONCLUSIONS

Severe RV dysfunction identified on cardiac CT was a significant prognostic factor for 1-year mortality in LTx candidates. Patients with severe RV dysfunction should be prioritized for LTx and classified as urgent due to their elevated short-term mortality risk. Cardiac CT may provide valuable prognostic information during the pretransplant evaluation process.

Evolving perspectives on aortic stenosis: the increasing importance of evaluating the right ventricle before aortic valve intervention

Aortic stenosis (AS) was historically considered a disease of the left side of the heart, with the main pathophysiological impact being predominantly on the left ventricle (LV). However, progressive pressure overload in AS can initiate a cascade of extra-valvular myocardial remodeling that could also precipitate maladaptive alterations in the structure and function of the right ventricle (RV). The haemodynamic and clinical importance of these changes in patients with AS have been largely underappreciated in the past. Contemporary data indicates that RV dilatation or impairment identifies the AS patients who are at increased risk of adverse clinical outcomes after aortic valve replacement (AVR). It is now increasingly recognised that effective quantitative assessment of the RV plays a key role in delineating the late clinical stage of AS, which could improve patient risk stratification. Despite the increasing emphasis on the pathological significance of RV changes in AS, it remains to be established if earlier detection of these changes can improve the timing for intervention. This review will summarise the features of normal RV physiology and the mechanisms responsible for RV impairment in AS. In addition, we will discuss the multimodality approach to the comprehensive assessment of RV size, function and mechanics in AS patients. Finally, we will review the emerging evidence reinforcing the negative impact of RV dysfunction on clinical outcomes in AS patients treated with AVR.

Atrial Functional Tricuspid Regurgitation: A Comprehensive Review of Pathophysiology, Diagnosis, and Management Strategies

Atrial fibrillation (AF), the most prevalent sustained cardiac arrhythmia, is intricately linked with atrial functional tricuspid regurgitation (AFTR), a condition distinguished from ventricular functional tricuspid regurgitation by its unique pathophysiological mechanisms and clinical implications. This review article delves into the multifaceted aspects of AFTR, exploring its epidemiology, pathophysiology, diagnostic evaluation, and management strategies. Further, we elucidate the mechanisms underlying AFTR, including tricuspid annular dilatation, right atrial enlargement, and dysfunction, which collectively contribute to the development of tricuspid regurgitation in the absence of significant pulmonary hypertension or left-sided heart disease. The section on diagnostic evaluation highlights the pivotal role of echocardiography, supplemented by cardiac magnetic resonance (CMR) imaging and computed tomography (CT), in assessing disease severity and guiding treatment decisions. Management strategies for AFTR are explored, ranging from medical therapy and rhythm control to surgical and percutaneous interventions, underscoring the importance of a tailored, multidisciplinary approach. Furthermore, the article identifies gaps in current knowledge and proposes future research directions to enhance our understanding and management of AFTR. By providing a comprehensive overview of AFTR, this review aims to raise awareness among healthcare professionals and stimulate further research to improve patient care and outcomes in this increasingly recognized condition.

Sex-Specific Insights into Etiology, Diagnosis, Treatment, and Prognosis in Significant Tricuspid Regurgitation: A Narrative Review

In recent decades, a burgeoning interest in tricuspid regurgitation (TR) has been prompted by a heightened awareness of its prevalence and the advent of dedicated percutaneous treatment approaches. Despite considerable understanding of its intricate anatomy and response to varying pressure and loading conditions, the impact of biological sex remains a subject of investigation. While TR typically afflicts more women, significant differences in TR etiology and post-treatment outcomes have not been conclusively established. This narrative review seeks to consolidate the latest evidence concerning sex-related nuances in anatomy, pathophysiology, diagnosis, treatment, and prognosis of significant tricuspid regurgitation. Through synthesizing this information, we aim to provide a comprehensive understanding of how sex may influence the management and prognosis of this condition.

Multimodality Imaging in the Management of Tricuspid Valve Regurgitation

Approximately 5% of elderly patients suffer from moderate or severe tricuspid valve regurgitation, which is an independent predictor of high morbidity and mortality. Surgical treatment of isolated tricuspid valve regurgitation has been associated with elevated fatality rate, leading to a growing interest in minimal invasive, transcatheter-based therapies such as transcatheter edge-to-edge repair and transcatheter valve replacement. Nevertheless, despite high procedural efficacy and safety of transcatheter-based therapies, a number of challenges limit their rapid adoption in routine clinical practice. In particular, the wide range of transcatheter approaches to address the significant variability in tricuspid valve pathology challenges the reproducibility of clinical outcomes. Multimodality imaging is pivotal for grading the regurgitation severity, determining the underlying pathology, assessing RV function and pulmonary pressures, identifying concomitant cardiac disease, and selecting the most beneficial treatment modality and access. This article reviews the role of different imaging modalities in guiding the management of patients with significant tricuspid valve regurgitation.

Cardiac Computed Tomography of Native Cardiac Valves

Valvular heart disease (VHD) is a significant clinical problem associated with high morbidity and mortality. Although not being the primary imaging modality in VHD, cardiac computed tomography (CCT) provides relevant information about its morphology, function, severity grading, and adverse cardiac remodeling assessment. Aortic valve calcification quantification is necessary for grading severity in cases of low-flow/low-gradient aortic stenosis. Moreover, CCT details significant information necessary for adequate percutaneous treatment planning. CCT may help to detail the etiology of VHD as well as to depict other less frequent causes of valvular disease, such as infective endocarditis, valvular neoplasms, or other cardiac pseudomasses.

Multimodality imaging for transcatheter tricuspid valve repair and replacement

Transcatheter tricuspid intervention is a rapidly evolving field with multiple classes of therapeutic devices currently in development. Procedural success in tricuspid intervention is predicated on appropriate device selection for patient specific anatomy and satisfactory imaging for intra-procedural guidance. This review will outline protocols and methodology for multi-modality imaging assessment of the tricuspid valve and associated structures, with emphasis on anatomic and functional characteristics that determine suitability for each class of tricuspid intervention. Intra-procedural imaging requirements for each class of device, with design and procedural imaging guidance of specific devices, will also be addressed.

Reference ranges of tricuspid annulus geometry in healthy adults using a dedicated three-dimensional echocardiography software package

Background

Tricuspid annulus (TA) sizing is essential for planning percutaneous or surgical tricuspid procedures. According to current guidelines, TA linear dimension should be assessed using two-dimensional echocardiography (2DE). However, TA is a complex three-dimensional (3D) structure.

Aim

Identify the reference values for TA geometry and dynamics and its physiological determinants using a commercially available three-dimensional echocardiography (3DE) software package dedicated to the tricuspid valve (4D AutoTVQ, GE).

Methods

A total of 254 healthy volunteers (113 men, 47 ± 11 years) were evaluated using 2DE and 3DE. TA 3D area, perimeter, diameters, and sphericity index were assessed at mid-systole, early- and end-diastole. Right atrial (RA) and ventricular (RV) end-diastolic and end-systolic volumes were also measured by 3DE.

Results

The feasibility of the 3DE analysis of TA was 90%. TA 3D area, perimeter, and diameters were largest at end-diastole and smallest at mid-systole. Reference values of TA at end-diastole were 9.6 ± 2.1 cm2 for the area, 11.2 ± 1.2 cm for perimeter, and 38 ± 4 mm, 31 ± 4 mm, 33 ± 4 mm, and 34 ± 5 mm for major, minor, 4-chamber and 2-chamber diameters, respectively. TA end-diastolic sphericity index was 81 ± 11%. All TA parameters were correlated with body surface area (BSA) (r from 0.42 to 0.58, p &lt; 0.001). TA 3D area and 4-chamber diameter were significantly larger in men than in women, independent of BSA (p &lt; 0.0001). There was no significant relationship between TA metrics with age, except for the TA minor diameter (r = −0.17, p &lt; 0.05). When measured by 2DE in 4-chamber (29 ± 5 mm) and RV-focused (30 ± 5 mm) views, both TA diameters resulted significantly smaller than the 4-chamber (33 ± 4 mm; p &lt; 0.0001), and the major TA diameters (38 ± 4 mm; p &lt; 0.0001) measured by 3DE. At multivariable linear regression analysis, RA maximal volume was independently associated with both TA 3D area at mid-systole (R2 = 0.511, p &lt; 0.0001) and end-diastole (R2 = 0.506, p &lt; 0.0001), whereas BSA (R2 = 0.526, p &lt; 0.0001) was associated only to mid-systolic TA 3D area.

Conclusions

Reference values for TA metrics should be sex-specific and indexed to BSA. 2DE underestimates actual 3DE TA dimensions. RA maximum volume was the only independent echocardiographic parameter associated with TA 3D area in healthy subjects.