Comprehensive Two-Dimensional Interrogation of the Tricuspid Valve Using Knowledge Derived from Three-Dimensional Echocardiography

Tricuspid valve and right-heart chamber remodelling in elderly subjects with secondary tricuspid regurgitation

BACKGROUND

The prevalence of secondary tricuspid regurgitation (TR) increases with ageing, but the exact mechanisms and the pattern of tricuspid valve (TV) remodelling are yet to be defined. This knowledge is needed to guide patient selection for the evolving therapeutic options. We sought to explore the prevalence and predictors of secondary TR in the elderly, as well as the associated pattern of right-heart chamber and TV remodelling.

METHODS

Consecutive older subjects (60-year-old or older) were prospectively enrolled and detailed analysis of right-heart chambers and TV was conducted (ClinicalTrials.gov ID: NCT05784883). TR severity was defined based on a multiparametric approach.

RESULTS

Out of 213 patients (age, 67.1 ± 5.9 years, 52.6% female), 48.8% had mild and 15.5% had moderate-severe TR. The frequency of moderate-severe TR increased from 4.5% in those without to 32.9% in those with underlying abnormalities of the left/right heart. There was a significant trend of worsening right-heart chamber and TV remodelling across the three grades of TR severity (none-trace, mild, and moderate-severe; p-value for linear trend < 0.001). ROC curve-defined cut-points of TV remodelling parameters predicting moderate-severe TR were annular dilatation ≥3.75 cm (AUC: 0.74), tenting area ≥1.45 cm2 (AUC: 0.67), and leaflet length ≥2.25 cm (AUC: 0.61) with increasing frequency of moderate-severe TR from 7.2% through 64.7%, in those with none vs. all three criteria (p < 0.001). The most important correlate of the three TV remodelling parameters was right ventricular and atrial (RV and RA) dilatation.

CONCLUSION

Rather than ageing per se, the presence of underlying cardiac abnormalities determines the frequency of moderate-severe TR. Progressive remodelling of right-heart chambers and TV geometry starts with the development of mild TR. TA dilatation, increased tenting, and leaflet elongation are three important correlates of the development of TR that parallel progressive RV and RA dilatation.Study Registration: ClinicalTrials.gov ID: NCT05784883.

Personalized Guidance of Edge-to-Edge Transcatheter Tricuspid Valve Repair by Multimodality Imaging

Background: Transcatheter edge-to-edge tricuspid valve repair (T-TEER) for tricuspid regurgitation (TR) is always guided by transesophageal echocardiography (TEE). As each patient has unique anatomy and acoustic window, adding transthoracic echocardiography (TTE) and cardiac CT could improve procedural planning and guidance. Objectives: We aimed to assess T-TEER success and outcomes of a personalized guidance approach, based on multimodality imaging (MMI) of patient-tailored four right-sided chamber views (four-right-ch), as depicted by CT, TTE, TEE and fluoroscopy. Methods: Patients were assigned to MMI or classical TEE guidance, depending on TTE acoustic window. In MMI patients, planning included cardiac CT, which determined the fluoroscopic angulations of the specific four-right-ch, while guidance relied heavily on TTE, with minimal intermittent TEE for leaflet grasping and result confirmation. Both TTE and TEE were matched to respective CT and fluoroscopy four-right-ch. TR severity and quality of life (QoL) parameters were assessed from baseline to 12 months. Results: A total of 40 T-TEER patients were included, with 17 procedures guided by MMI and 23 solely by TEE. Baseline characteristics were similar between groups, e.g., age (83.1 ± 4.1 vs. 81 ± 5.3, p = 0.182) or STS-Score (11.1 ± 7.4% vs. 10.6 ± 5.9%, p = 0.813). The primary efficacy endpoint of ≥one-grade TR reduction at 30 days was 94% (16/17) in MMI vs. 91% (21/23) in TEE patients, with two or more TR grade reduction in 65% vs. 52% (p = 0.793). Device success was overall 100%, with no device-related complications, but three TEE-associated cases of gastrointestinal bleeding in the TEE-only group. By 12 months, all 15 MMI and 19 TEE survivors improved NYHA functional class and QoL, e.g., Kansas City Cardiomyopathy Questionnaire Score Δ29.6 ± 6.7 vs. 21.9 ± 5.8 (p = 0.441) pts., 6-min walk distance Δ101.5 ± 36.4 vs. 85.7 ± 32.1 (p = 0.541) meters. Conclusions: In a subset of patients with good TTE acoustic window, MMI guidance of T-TEER is effective and seems to avoid gastroesophageal injuries caused by TEE probe manipulation. TR reduction, irrespective of guidance method, impacts long-term QoL.

Heterozygous nonsense variants in laminin subunit 3α resulting in Ebstein's anomaly

Ebstein's anomaly is a rare congenital heart disease characterized by tricuspid valve downward displacement and is associated with additional cardiac phenotypes such as left ventricle non-compaction. The genetic basis of Ebstein's anomaly has yet to be fully elucidated, although several genes (e.g., NKX2-5, MYH7, TPM1, and FLNA) may contribute to Ebstein's anomaly. Here, in two Ebstein's anomaly families (a three-generation family and a trio), we identified independent heterozygous nonsense variants in laminin subunit 3 α (LAMA3), cosegregated with phenotypes in families with reduced penetrance. Furthermore, knocking out Lama3 in mice revealed that haploinsufficiency of Lama3 led to Ebstein's malformation of the tricuspid valve and an abnormal basement membrane structure. In conclusion, we identified a novel gene-disease association of LAMA3 implicated in Ebstein's anomaly, and the findings extended our understanding of the role of the extracellular matrix in Ebstein's anomaly etiology.

Three-dimensional echocardiography of the tricuspid valve

Due to the proportionally high mortality rates associated with isolated tricuspid valve surgery, the invasive treatment of such pathology, historically, has been left largely unaddressed. Recently, there has been an appreciation for the mortality and morbidity of tricuspid valve disease, giving rise to the movement towards identifying less invasive, transcatheter approaches for treatment. Due to the technical complexity of these procedures along with the uniqueness and variability of tricuspid valve anatomy, a better appreciation of the tricuspid valve anatomy and pathology is required for pre-procedural planning. While two-dimensional echocardiography serves as the initial non-invasive modality for tricuspid valve evaluation, three-dimensional echocardiography provides a complete en face view of the tricuspid valve and surrounding structures, as well contributes further information regarding disease etiology and severity. In this review, we discuss the utility of three-dimensional echocardiography as a supplement to two-dimensional imaging to better assess tricuspid valve disease and anatomy to aide in future innovative therapies.

Tricuspid Regurgitation in Acute Heart Failure: Predicting Outcome Using Novel Quantitative Echocardiography Techniques

Background: The prognostic impact of tricuspid regurgitation (TR) in acute heart failure (AHF) remains uncertain. Methods: We retrospectively assessed 418 consecutive AHF patients who underwent comprehensive echocardiographic assessment within 24 h of study recruitment. TR was quantitatively assessed with 3 guideline-directed measures: regurgitant volumes (RgVol), effective regurgitant orifice area (ERO) and vena contracta (VC) diameter. Disproportionate TR was assessed by the ratio of the VC diameter to the tricuspid annulus diameter (VC/TA) ≥ 0.24. Results: The prevalence of significant (i.e., >mild) TR differed when various standard assessment parameters were applied to quantification: RgVol 50.3% (173/344), ERO 75.6% (260/344) and VC diameter 94.6% (335/354). None were able to delineate those at excess risk of all-cause 2-year mortality using guideline-directed cut-offs of mild, moderate and severe TR. Using a cut-off of VC/TA ≥ 0.24, we identified that 36.9% (130/352) had “disproportionate” TR. Disproportionate TR was associated with an excess risk of mortality at 2 years compared to proportionate TR; HR 1.48 (95% CI 1.06−2.06 [p = 0.02]) which was not significant on multivariate assessment (p = 0.94). Conclusions: TR was not associated with outcome in AHF using guideline measures. A new assessment of “Disproportionate” TR carries a higher risk than proportionate TR but was not related to outcome based on multivariate analysis. Further research is needed to quantify TR more effectively to identify cut-offs for future guidelines and disproportionate TR may be an important part of Heart Failure 2.0.

Different Causes of Functional Tricuspid Valve Regurgitation Are Linked to Differences in Tricuspid Valve and Right-Sided Heart Geometry and Function: 3D Echocardiography Study

Background and Objectives: The aim of this study was to clarify the tricuspid valve (TV) and right ventricular (RV) geometry and function characteristics using 3D echocardiography-based analysis and to identify echocardiographic predictors for severe tricuspid regurgitation (TR) in different etiologies of functional TR (fTR). Methods and Results: The prospective study included 128 patients (median age 64 years, 57% females): 109 patients with moderate or severe fTR (69-caused by dominant left-sided valvular pathology (LSVP), 40 due to precapillary pulmonary hypertension (PH)), and 19 healthy controls. The 2D and 3D-transthoracic echocardiography analysis included TV, right atrium, RV geometry, and functional parameters. All the RV geometry parameters as well as 3D TV parameters were increased in both fTR groups when compared to controls. Higher RV diameters, length, areas, volumes, and more impaired RV function were in PH group compared to LSVP group. PH was associated with larger leaflet tenting height, volume, and more increased indices of septal-lateral and major axis tricuspid annulus (TA) diameters. LVSP etiology was associated with higher anterior-posterior TA diameter and sphericity index. Univariate and multivariate logistic regression and ROC analyses revealed that different fTR etiologies were associated with various 2D and 3D echocardiographic parameters to predict severe TR: major axis TA diameter and TA perimeter, the leaflet tenting volume had the highest predictive value in PH group, septal-lateral systolic TA diameter-in LSVP group. The 3D TA analysis provided more reliable prediction for severe fTR. Conclusions: TV and RV geometry vary in different etiologies of functional TR. Precapillary PH is related to more severe RV remodeling and dysfunction and changes of TV geometry, when compared to LSVP group. The 3D echocardiography helps to determine echocardiographic predictors of severe TR in different fTR etiologies.

Developing Insights Regarding Tricuspid Valve Regurgitation: Morphology, Assessment of Severity, and the Need for a Novel Grading Scheme

Current understanding that progressive tricuspid regurgitation (TR) is associated with worse outcomes has highlighted the clinical need for a more accurate assessment of TR morphology and severity. This need has been further emphasized owing to the development of a myriad of percutaneous right-sided interventions, which may offer successful treatment of TR in selected patients. Understanding the etiology and quantification of the severity of TR has important implications in the selection of novel therapeutic strategies, i.e., medical vs. percutaneous vs. surgical approaches. Newer grading schemas that better reflect the TR lesion severity have been recently proposed and may facilitate monitoring of the evolution of TR following percutaneous and/or surgical treatment. In this review, we summarize contemporary concepts regarding tricuspid valve morphology, TR etiology, and associated mechanisms and echocardiographic approaches to grade TR severity.

Multi-modality imaging assessment of native valvular regurgitation: an EACVI and ESC council of valvular heart disease position paper

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Imaging is pivotal in the evaluation of native valve regurgitation and echocardiography is the primary imaging modality for this purpose. The imaging assessment of valvular regurgitation should integrate quantification of the regurgitation, assessment of the valve anatomy and function, and the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation largely relies on the results of imaging. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing native valve regurgitation. The present document aims to present clinical guidance for the multi-modality imaging assessment of native valvular regurgitation.

Anatomy of the Tricuspid Valve and Pathophysiology of Tricuspid Regurgitation

Transcatheter valve interventions have seen a significant increase in the past decade. The combination of improved techniques and available tools provides less invasive options supplementing surgical therapies. The tricuspid valve (TV) apparatus is a complex structure between the right atrium and the right ventricle; it generally consists of 3 leaflets (anterior, posterior, and septal) inserted in the fibrous tricuspid annulus and connected to the papillary muscle via the chordae tendinae. This article reviews TV anatomy, the pathophysiology of tricuspid regurgitation, and multimodality imaging to study TV, as well as provides an overview of transcatheter TV intervention.

Imaging for transcatheter native tricuspid valve intervention: patient selection, procedural planning and interventional guidance

There are an increasing number of transcatheter tricuspid valve interventions being performed worldwide using commercially available and investigational devices. Imaging in the pre-procedural and periprocedural period is essential for procedural and clinical success. Echocardiographic-based techniques are particularly important in these procedures, especially for interventional guidance. This review summarizes the current devices in use and how imaging is used for patient selection, procedural planning, and interventional guidance. The most commonly used method of transcatheter tricuspid intervention is edge-to-edge repair using the MitraClip or TriClip devices (Abbott, Santa Clara, CA, USA). Randomized controlled data is pending but observational studies have demonstrated success, especially in the setting of smaller coaptation gaps and adequate transesophageal imaging windows. Direct annuloplasty with the Cardioband (Edwards Lifesciences, Irvine, CA, USA) has also been used in many centers and has demonstrated success when the anatomy and mechanism of tricuspid regurgitation are appropriate for annuloplasty based on imaging evaluation. Lastly, transcatheter valve replacement is becoming more common using several investigational devices and relies heavily on imaging methods to achieve procedural success.

Multimodality cardiac imaging and new display options to broaden our understanding of the tricuspid valve

PURPOSE OF REVIEW

The prognostic impact of tricuspid regurgitation (TR) and the subsequent development of percutaneous procedures targeting the tricuspid valve (TV), has brought to the forefront the role of imaging for the assessment of the forgotten valve. As illustrated in several studies and summarized in this review, currently a multimodality imaging approach is required to understand the pathophysiology of TR, due to the complex TV anatomy and the close relationship between the severity of TR and the extent of the remodeling of the right heart chambers.

RECENT FINDINGS

Recently, the advance in the tranhscatheter treatment of the TV has led to a growing interest in the development of dedicated software packages and new display modalities to increase our understanding of the TV. As a consequence, a transversal knowledge of the different imaging modalities is required for contemporary cardiac-imaging physicians.

SUMMARY

This review highlights the main features, and the pros and cons of echocardiography, cardiac computed tomography, cardiac magnetic resonance and emerging technologies, as 3D printing and virtual reality, in the assessment of patients with TR.

Assessment of tricuspid annulus: anatomic and echocardiographic correlation

Tricuspid regurgitation is associated with a poor outcome and its quantification remains a challenge. Tricuspid annulus dilatation is one of the parameters that influences clinical decision-making. The aim of this study was to compare the use of 2D transoesophageal echocardiography with surgical assessment for the measurement of the tricuspid annulus. Sixty-one cardiac patients (median age 64 years) were included in the study. Echocardiographic tricuspid annulus measurements were obtained from four chamber and transgastric short axis views and compared with the surgical measurements of this valve. The study was approved by the Ethics Committee of our institution. The tricuspid annulus measurements were obtained from the four chamber and the short axis views in 57 and 49 patients, respectively, while surgical measurement was performed in all 61 patients. Bland-Altman analysis of 49 tricuspid annulus-matched dimensions of the short axis view and surgical values showed a mean bias of 0.223 mm/m², with limits of agreement of -5.86 to 6.31 mm/m². Echocardiographic measurements of the tricuspid annulus dimension were accurate (90% sensitivity and 90% specificity for a four chamber view cut-off value ≥ 24.5 mm/m², and 89% sensitivity and 97% specificity for a short axis view cut-off value ≥ 37.6 mm/m², P < 0.0001; both cases) for detecting directly assessed annular dilatation by the surgeon in the operative field. Echocardiographic values of tricuspid annulus dimension have a good predictive value to detect surgically assessed annular dilatation and may help identify patients who require surgical tricuspid intervention.

Novelties in 3D Transthoracic Echocardiography

Cardiovascular imaging is developing at a rapid pace and the newer modalities, in particular three-dimensional echocardiography, allow better analysis of heart structures. Identifying valve lesions and grading their severity represents crucial information and nowadays is strengthened by the introduction of new software, such as transillumination, which provide detailed morphology descriptions. Chambers quantification has never been so rapid and accurate: machine learning algorithms generate automated volume measurements, including left ventricular systolic and diastolic function, which is extremely important for clinical decisions. This review provides an overview of the latest innovations in the echocardiography field, and is helpful by providing a better insight into heart diseases.

A pilot in silico modeling-based study of the pathological effects on the biomechanical function of tricuspid valves

Current clinical assessment of functional tricuspid valve regurgitation relies on metrics quantified from medical imaging modalities. Although these clinical methodologies are generally successful, the lack of detailed information about the mechanical environment of the valve presents inherent challenges for assessing tricuspid valve regurgitation. In the present study, we have developed a finite element-based in silico model of one porcine tricuspid valve (TV) geometry to investigate how various pathological conditions affect the overall biomechanical function of the TV. There were three primary observations from our results. Firstly, the results of the papillary muscle (PM) displacement study scenario indicated more pronounced changes in the TV biomechanical function. Secondly, compared to uniform annulus dilation, nonuniform dilation scenario induced more evident changes in the von Mises stresses (83.8-125.3 kPa vs 65.1-84.0 kPa) and the Green-Lagrange strains (0.52-0.58 vs 0.47-0.53) for the three TV leaflets. Finally, results from the pulmonary hypertension study scenario showed opposite trends compared to the PM displacement and annulus dilation scenarios. Furthermore, various chordae rupture scenarios were simulated, and the results showed that the chordae tendineae attached to the TV anterior and septal leaflets may be more critical to proper TV function. This in silico modeling-based study has provided a deeper insight into the tricuspid valve pathologies that may be useful, with moderate extensions, for guiding clinical decisions. NOVELTY STATEMENT: The novelties of the research are summarized below: A comprehensive in silico pilot study of how isolated functional tricuspid regurgitation pathologies and ruptured chordae tendineae would alter the tricuspid valve function; An extensive analysis of the tricuspid valve function, including mechanical quantities (eg, the von Mises stress and the Green-Lagrange strain) and clinically-relevant geometry metrics (eg, the tenting area and the coaptation height); and A developed computational modeling pipeline that can be extended to evaluate patient-specific tricuspid valve geometries and enhance the current clinical diagnosis and treatment of tricuspid regurgitation.

A Complex Tricuspid Clip

We present this case of a 22-year-old woman with congenital heart disease as the youngest reported patient, to the best of our knowledge, to successfully undergo treatment of medically refractory torrential tricuspid regurgitation with the MitraClip system as an adjunct to guideline directed therapy. (Level of Difficulty: Advanced.)

Imaging and Patient Selection for Transcatheter Tricuspid Valve Interventions

With the emergence of transcatheter solutions for the treatment of tricuspid regurgitation (TR) increased attention has been directed to the once neglected tricuspid valve (TV) complex. Recent studies have highlighted new aspects of valve anatomy and TR etiology. The assessment of valve morphology along with quantification of regurgitation severity and RV function pose several challenges to cardiac imagers guiding transcatheter valve procedures. This review article aims to give an overview over the role of modern imaging modalities during assessment and treatment of the TV.

The tricuspid valve in review: anatomy, pathophysiology and echocardiographic assessment with focus on functional tricuspid regurgitation

The tricuspid valve (TV) is a complex anatomical structure that incorporates a saddle-shaped annulus, asymmetric leaflets, the subvalvular apparatus and the right ventricle and its loading conditions. In this paper, an appreciation of the normal anatomy and physiology of the TV is reviewed before discussing functional tricuspid regurgitation (TR), a disease that has garnered renewed interest due to increased awareness of adverse outcomes and novel transcatheter therapeutic options. Two and three-dimensional echocardiographic imaging of the TV using transthoracic and transesophageal windows are subsequently discussed. The future of cardiovascular medicine will have more to offer the “forgotten” right-sided chambers and valves, and this review aims to refresh knowledge and enthusiasm around the forgotten but crucially important TV.

3-Dimensional Echocardiography in Imaging the Tricuspid Valve

Tricuspid regurgitation (TR) is an independent predictor of death. Lately, emerging technologies for the treatment of TR have increased the interest of physicians. Due to the complex 3-dimensional (3D) geometry of the tricuspid valve (TV) and its anterior position in the mediastinum, conventional 2D echocardiography is unsuitable to study the anatomy and pathophysiologic mechanisms of the regurgitant TV. 3D echocardiography has emerged as a very cost-effective imaging modality with which to: 1) visualize the TV anatomy; 2) define the mechanism of TR; 3) measure the size and geometry of the tricuspid annulus; 4) analyze the anatomic relationships between TV apparatus and surrounding cardiac structures; 5) assess volumes and function of the right atrium and ventricle; and 6) plan surgical repair or guide and monitor transcatheter interventional procedures.

Role of 3-Dimensional Echocardiography in the Comprehensive Evaluation of the Tricuspid Valve in Patients With Tricuspid Regurgitation

Three-dimensional echocardiography is one of the most promising methods for the diagnosis of valvular heart disease, and recently has become an essential clinical tool owing to the continued development of real-time transesophageal echocardiography (TEE) technology. And now an era of renewed interest and enthusiasm surrounding the diagnosis and treatment of valvular heart disease has come, which is driven by emerging trans-catheter procedures. Nonetheless, little or no attention has been given to the treatment of tricuspid regurgitation (TR). The application of 3D-TEE is useful for simultaneous visualization of all 3 leaflets in order to grasp the whole picture of the tricuspid valve (TV; “en face” view). The implications of 3-D assessment of TV annulus, leaflets, and morphology involve an improved understanding of both the mechanics and treatment of TR. This method has been useful for surgical management, including accurate measurement of tricuspid annular diameter and prediction of the post-surgical outcome. Moreover, this method may be indispensable for detailed and comprehensive evaluation of the TV in patients with TR who are candidates for trans-catheter tricuspid procedures. In addition, color Doppler 3D-TEE has been valuable to identify the location of the regurgitant orifice and the severity of the TR. It is now clear that this method will enhance the diagnosis and management of TR patients.

Fluoroscopic Anatomy of Right-Sided Heart Structures for Transcatheter Interventions

Performing transcatheter tricuspid valve interventions requires a thorough knowledge of right-heart imaging. Integration of chamber views across the spectrum of imaging modalities (i.e., multislice computed tomography, fluoroscopy, and echocardiography) can facilitate transcatheter interventions on the right heart. Optimal fluoroscopic viewing angles for guiding interventional procedures can be obtained using pre-procedural multislice computed tomography scans. The present paper describes fluoroscopic viewing angles necessary to appreciate right-heart chamber anatomy and their relationship to echocardiography using multislice computed tomography.

Mechanics of the Tricuspid Valve-From Clinical Diagnosis/Treatment, In-Vivo and In-Vitro Investigations, to Patient-Specific Biomechanical Modeling

Proper tricuspid valve (TV) function is essential to unidirectional blood flow through the right side of the heart. Alterations to the tricuspid valvular components, such as the TV annulus, may lead to functional tricuspid regurgitation (FTR), where the valve is unable to prevent undesired backflow of blood from the right ventricle into the right atrium during systole. Various treatment options are currently available for FTR; however, research for the tricuspid heart valve, functional tricuspid regurgitation, and the relevant treatment methodologies are limited due to the pervasive expectation among cardiac surgeons and cardiologists that FTR will naturally regress after repair of left-sided heart valve lesions. Recent studies have focused on (i) understanding the function of the TV and the initiation or progression of FTR using both in-vivo and in-vitro methods, (ii) quantifying the biomechanical properties of the tricuspid valve apparatus as well as its surrounding heart tissue, and (iii) performing computational modeling of the TV to provide new insight into its biomechanical and physiological function. This review paper focuses on these advances and summarizes recent research relevant to the TV within the scope of FTR. Moreover, this review also provides future perspectives and extensions critical to enhancing the current understanding of the functioning and remodeling tricuspid valve in both the healthy and pathophysiological states.

Assessment of tricuspid valve by two- and three-dimensional echocardiography with special reference to percutaneous repair and prosthetic valve implantation procedures

Moderate-to-severe tricuspid regurgitation affects approximately 1.6 million people in the United States. An estimated 8000 patients will undergo tricuspid surgery annually, leaving a large number of patients with this condition untreated. Many of these individuals who are not referred for surgery engender a large unmet clinical need; this may be primarily due to the surgical risk involved. In persons who are categorized as high-risk surgical candidates, percutaneous procedures present a viable alternative. The majority of developmental attention as regards percutaneous approaches has been focused on the aortic and mitral valves recently, but few data are available about the feasibility and efficacy of minimally invasive tricuspid valve treatment. We review the usefulness of two- and three-dimensional echocardiography in the assessment of the tricuspid valve with special reference to recent interest in percutaneous repair and prosthetic valve implantation procedures for severe functional tricuspid regurgitation.

Three-dimensional Tricuspid Area. A New Criterion to Improve Patient Selection for Annuloplasty in Tricuspid Regurgitation

INTRODUCTION AND OBJECTIVES

Late functional tricuspid regurgitation after rheumatic left-sided valve surgery is an important predictor of poor prognosis. This study investigated the usefulness and accuracy of 3-dimensional transthoracic echocardiography tricuspid area compared with conventional 2-dimensional diameter (2DD) for assessing significant tricuspid annulus dilatation, providing cutoff values that could be used in clinical practice to improve patient selection for surgery.

METHODS

We prospectively included 109 patients with rheumatic heart disease in the absence of previous valve replacement. Tricuspid regurgitation was divided into 3 groups: mild, moderate, and severe. Optimal 3-dimensional area (3DA) and 2DD cutoff points for identification of significant tricuspid annulus dilatation were obtained and compared with current guideline thresholds. Predictive factors for 3DA dilatation were also assessed.

RESULTS

Optimal cutoff points for both absolute and adjusted to body surface area (BSA) tricuspid annulus dilatation were identified (3DA: 10.4 cm², 6.5 cm²/m²; 2DD: 35 mm, 21 mm/m²); 3DA/BSA had the best diagnostic performance (AUC=0.83). Three-dimensional transthoracic echocardiography tricuspid area helped to reclassify surgical indication in 14% of patients with mild tricuspid regurgitation (95%CI, 1%-15%; P=.03) and 37% with moderate tricuspid regurgitation (95%CI, 22%-37%; P<.0001), whereas 3DA/BSA changed surgery criteria in cases of mild tricuspid regurgitation (17%; 95%CI, 3%-17%; P=.01) compared with 2DD/BSA. On multivariable analysis, right and left atrial volumes and basal right ventricle diameter were independently correlated with 3DA.

CONCLUSIONS

The current 40 mm threshold underestimates tricuspid annulus dilatation. Although 21 mm/m² seems to be a reasonable criterion, the combination with 3DA assessment improves patient selection for surgery.

3D printing of normal and pathologic tricuspid valves from transthoracic 3D echocardiography data sets

Aims

To explore the feasibility of using transthoracic 3D echocardiography (3DTTE) data to generate 3D patient-specific models of tricuspid valve (TV).

Methods and Results

Multi-beat 3D data sets of the TV (32 vol/s) were acquired in five subjects with various TV morphologies from the apical approach and analysed offline with custom-made software. Coordinates representing the annulus and the leaflets were imported into MeshLab (Visual Computing Lab ISTICNR) to develop solid models to be converted to stereolithographic file format and 3D print. Measurements of the TV annulus antero-posterior (AP) and medio-lateral (ML) diameters, perimeter (P), and TV tenting height (H) and volume (V) obtained from the 3D echo data set were compared with those performed on the 3D models using a caliper, a syringe and a millimeter tape. Antero-posterior (4.2 ± 0.2 cm vs. 4.2 ± 0 cm), ML (3.7 ± 0.2 cm vs. 3.6 ± 0.1 cm), P (12.6 ± 0.2 cm vs. 12.7 ± 0.1 cm), H (11.2 ± 2.1 mm vs. 10.8 ± 2.1 mm) and V (3.0 ± 0.6 ml vs. 2.8 ± 1.4 ml) were similar (P = NS for all) when measured on the 3D data set and the printed model. The two sets of measurements were highly correlated (r = 0.991). The mean absolute error (2D - 3D) for AP, ML, P and tenting H was 0.7 ± 0.3 mm, indicating accuracy of the 3D model of <1 mm.

Conclusion

Three-dimensional printing of the TV from 3DTTE data is feasible with highly conserved fidelity. This technique has the potential for rapid integration into clinical practice to assist with decision-making, surgical planning, and teaching.

Evaluation of the right ventricle by echocardiography: particularities and major challenges

INTRODUCTION

Compared with the left ventricle (LV), the right ventricle (RV) is less suited for evaluation by echocardiography (ECHO). Nevertheless, RV ECHO-assessment has currently emerged as an important diagnostic tool with meaningful prognostic value and essential contribution to therapeutic decisions. Although significant progress has been made, including generation of higher-quality normative data, validation of several two-dimensional measurements and improvements in three-dimensional ECHO-techniques, many challenges in RV ECHO-assessment still persist. Areas covered: This review discusses the particular challenges and limits in obtaining accurate measurements of RV anatomical and functional parameters and focuses primarily on the difficulties in proper interpretation of the highly load dependent RV ECHO-parameters which complicates the use of this valuable diagnostic and surveillance technique. Expert commentary: There is increasing evidence that RV assessment in relation with its actual loading conditions by ECHO-derived composite variables, which either incorporate a certain functional parameter and load, or incorporate measures which reflect the relationship between RV dilation and RV load, considering also the right atrial pressure (i.e. 'load adaptation index'), is particularly suited for clinical decision-making. Load dependency of RV ECHO-parameters must be taken into consideration especially in patients with advanced RV dysfunction scheduled for LV assist device implantation or lung transplantation.

Interventional Imaging of the Tricuspid Valve

Nowadays, reasonable transcatheter tricuspid valve (TV) interventions are emerging as therapeutic options for functional tricuspid regurgitation (TR). The preprocedural planning is based on a multimodality imaging approach, which aims to (1) define the mechanisms of TR, (2) characterize TV morphology, (3) analyze the anatomic relationship between the TV apparatus and other structures, and (4) determine the size of the tricuspid annulus and vena cavae. Intraprocedural guidance is based mainly on transesophageal echocardiography (seldom transthoracic) and fluoroscopy, with the recent introduction of fusion imaging.

3D and 4D Ultrasound: Current Progress and Future Perspectives

PURPOSE OF REVIEW

Three-dimensional (3D) echocardiography (3DE) and 4-dimensional echocardiography (4DE), also known as real-time (RT) 3DE (RT3DE), are rapidly emerging technologies which have made significant impact in the clinical arena over the years. This review will discuss the recent applications of 3DE in diagnosing and treating different types of cardiovascular disease.

RECENT FINDINGS

Recent studies using 3DE expanded on prior findings and introduced additional applications to different cardiac conditions. Some studies have used 3D parameters to prognosticate long-term outcomes. Numerous innovative software designs including fully automated algorithms have been introduced to better evaluate valvular heart disease and cardiac function.

SUMMARY

With further evolution of 3DE technologies, this imaging modality will emerge as a powerful tool and likely become the imaging modality of choice in the diagnosis and management of various cardiac disorders.

Role of Echocardiography in Transcatheter Valvular Heart Disease Interventions

PURPOSE OF REVIEW

Transcatheter valvular interventions have increased in importance and utility for surgical valve repair and replacement. Cardiac imaging is the most crucial aspect of procedural planning and guidance. Echocardiography is a widely used, portable, and dynamic imaging modality used for many of these interventions. This review will summarize the role echocardiography in structural heart valvular interventions.

RECENT FINDINGS

Intraprocedural echocardiographic guidance has been a mainstay of structural heart interventions. Over the years, the use of 3-dimensional echocardiography has increased, and studies have shown utility in paravalvular leak prediction in the setting of transcatheter aortic valve replacement, procedural guidance in MitraClip repair, and in mitral and tricuspid valve therapies. Intraprocedural echocardiography is of paramount important for procedural success during all structural heart valvular interventions. Continued use of 2 and 3-dimensional echocardiography will be a major factor in driving the innovative field of structural heart interventions forward.

Current Clinical Applications of Three-Dimensional Echocardiography: When the Technique Makes the Difference

Advances in ultrasound, computer, and electronics technology have permitted three-dimensional echocardiography (3DE) to become a clinically viable imaging modality, with significant impact on patient diagnosis, management, and outcome. Thanks to the inception of a fully sampled matrix transducer for transthoracic and transesophageal probes, 3DE now offers much faster and easier data acquisition, immediate display of anatomy, and the possibility of online quantitative analysis of cardiac chambers and heart valves. The clinical use of transthoracic 3DE has been primarily focused, albeit not exclusively, on the assessment of cardiac chamber volumes and function. Transesophageal 3DE has been applied mostly for assessing heart valve anatomy and function. The advantages of using 3DE to measure cardiac chamber volumes derive from the lack of geometric assumptions about their shape and the avoidance of the apical view foreshortening, which are the main shortcomings of volume calculations from two-dimensional echocardiographic views. Moreover, 3DE offers a unique realistic en face display of heart valves, congenital defects, and surrounding structures allowing a better appreciation of the dynamic functional anatomy of cardiac abnormalities in vivo. Offline quantitation of 3DE data sets has made significant contributions to our mechanistic understanding of normal and diseased heart valves, as well as of their alterations induced by surgical or interventional procedures. As reparative cardiac surgery and transcatheter procedures become more and more popular for treating structural heart disease, transesophageal 3DE has expanded its role as the premier technique for procedure planning, intra-procedural guidance, as well as for checking device function and potential complications after the procedure.

Functional Tricuspid Regurgitation Caused by Chronic Atrial Fibrillation

Background—

Functional tricuspid regurgitation (TR) with a structurally normal tricuspid valve (TV) may occur secondary to chronic atrial fibrillation (AF). However, the clinical and echocardiographic differences according to functional TR subtypes are unclear. Therefore, characterization of functional TR because of chronic AF (AF-TR) remains undetermined.

Methods and Results—

To investigate the prevalence of AF-TR, 437 patients with moderate to severe TR underwent 3-dimensional (3D) transesophageal echocardiography. TR severity was determined by the averaged vena contracta width on apical and parasternal inflow views. The prevalence of AF-TR was 9.2%, whereas that of functional TR because of left-sided heart disease was 45.3%. Clinical features of AF-TR included advanced age, female sex, greater right atrial than left atrial enlargement and lower systolic pulmonary artery pressure compared with left-sided heart disease-TR with sinus rhythm (all P <0.05). In 3D TV assessment, patients with AF-TR had a larger TV annular area with weaker annular contraction (both P <0.001) but a smaller tethering angle ( P <0.001) despite a similar leaflet coaptation status compared with patients with left-sided heart disease-TR with sinus rhythm. On multivariable analysis, only the TV annular area in midsystole (coefficient, 0.059; 95% confidence interval, 0.041–0.078 per 100 mm 2 ; P <0.001) was associated with TR severity in AF-TR. The annular area was more closely correlated with the right atrial volume than right ventricular end-systolic volume in AF-TR ( P <0.001).

Conclusions—

AF-TR is not rare and is associated with advanced age and right atrial enlargement. TV deformations and their association with right heart remodeling differ between AF-TR and left-sided heart disease-TR. Our results suggest that in patients with TR secondary to AF, TV annuloplasty should be effective because this entity has annular dilatation without leaflet deformation.

State-of-the-Art Review of Echocardiographic Imaging in the Evaluation and Treatment of Functional Tricuspid Regurgitation

Functional or secondary tricuspid regurgitation (TR) is the most common cause of severe TR in the Western world. The presence of functional TR, either isolated or in combination with left heart disease, is associated with unfavorable natural history. Surgical mortality for isolated tricuspid valve interventions remains higher than for any other single valve surgery, and surgical options for repair do not have consistent long-term durability. In addition, as more patients undergo transcatheter left valve interventions, developing transcatheter solutions for functional TR has gained greater momentum. Numerous transcatheter devices are currently in early clinical trials. All patients require an assessment of valve morphology and function, and transcatheter devices typically require intraprocedural guidance by echocardiography. The following review will describe tricuspid anatomy, define echocardiographic views for evaluating tricuspid valve morphology and function, and discuss imaging requirements for the current transcatheter devices under development for the treatment of functional TR.

Assessment of pulmonary artery pressure by echocardiography-A comprehensive review

Pulmonary hypertension is a pathological haemodynamic condition defined as an increase in mean pulmonary arterial pressure ≥ 25 mmHg at rest, assessed using gold standard investigation by right heart catheterisation. Pulmonary hypertension could be a complication of cardiac or pulmonary disease, or a primary disorder of small pulmonary arteries. Elevated pulmonary pressure (PAP) is associated with increased mortality, irrespective of the aetiology. The gold standard for diagnosis is invasive right heart catheterisation, but this has its own inherent risks. In the past 30 years, immense technological improvements in echocardiography have increased its sensitivity for quantifying pulmonary artery pressure (PAP) and it is now recognised as a safe and readily available alternative to right heart catheterisation. In the future, scores combining various echo techniques can approach the gold standard in terms of sensitivity and accuracy, thereby reducing the need for repeated invasive assessments in these patients.

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Raised artery pulmonary pressure (PAP) is associated with increased mortality.

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We review the eight published echo techniques to assess PAP by echocardiography.

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Knowledge of all the echo techniques could avoid need for invasive tests.

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A scoring system combining various echo-derived measurements of PAP is needed.