Computed tomography imaging needs for novel transcatheter tricuspid valve repair and replacement therapies

Management of patients with transvalvular right ventricular leads undergoing transcatheter tricuspid valve interventions: a scientific statement of the European Heart Rhythm Association and the European Association of Percutaneous Cardiovascular Interventions of the ESC endorsed by the Heart Rhythm Society, the Asian Pacific Heart Rhythm Society and the Canadian Heart Rhythm Society

Up to one-third of patients referred for transcatheter tricuspid valve intervention (TTVI) have a transvalvular pacemaker (PPM) or implantable cardioverter-defibrillator (ICD) lead in place. Both the electrophysiology and interventional cardiology communities have been alerted to the complexity of decision-making in this situation due to potential interactions between the leads and the TTVI material, including the risk of jailing or damage to the leads. This document, commissioned by the European Heart Rhythm Association and the European Association of Percutaneous Cardiovascular Interventions of the ESC, reviews the scientific evidence to inform Heart Team discussions on the management of patients with a PPM or ICD who are scheduled for or have undergone TTVI.

Tricuspid Regurgitation: Knowledge of Tricuspid Valve Morphology, Etiology of Regurgitation, and Grading of Regurgitation Severity

With the aging of the population, the number of patients with tricuspid regurgitation (TR) is increasing. Severe TR is associated with global morbidity and mortality of cardiovascular events. In recent years, the rapid development of transcatheter interventions for tricuspid valve disease has made TR a current research hotspot. More preoperative information about the patient's tricuspid valve anatomy, the etiology leading to TR, and the severity of TR will aid in intraoperative maneuvers and postoperative prognosis assessments.

[Research of tricuspid regurgitation associated with cardiac implantable electronic devices]

Tricuspid regurgitation associated with cardiac implantable electronic devices (CIED) constitutes a significant subset of secondary tricuspid regurgitation, characterized by a multifactorial etiology involving pacing lead-mediated mechanical interference and CIED-related systemic factors. The pathogenesis of CIED-related tricuspid regurgitation encompasses direct mechanical trauma or functional disruption of the tricuspid valve apparatus by pacing leads, pacing mode-induced hemodynamic alterations, and clinical risk factors such as permanent atrial fibrillation, apical pacing, and high right ventricular pacing burden. The natural progression and clinical outcomes of CIED-related tricuspid regurgitation parallel those of tricuspid regurgitation stemming from other etiologies. Advanced imaging modalities, including echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging, enable precise diagnosis and longitudinal assessment of CIED-related tricuspid regurgitation. Management strategies emphasize multidisciplinary collaboration as well as integration of preventive approaches-such as refined lead implantation techniques and tailored pacing modalities-with therapeutic interventions ranging from pharmacotherapy to surgical valve repair or replacement. This article reviews the current understanding of CIED-related tricuspid regurgitation to provide a reference for clinical practice and research.

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.

Current Status of CT Imaging Before Common Transcatheter Interventions for Structural Heart Disease

Background: Over the past decade, several trials and observational studies have validated the use of minimally invasive cardiac interventions as viable treatment options for various cardiac diseases. Transcatheter techniques for severe aortic valve stenosis have rapidly emerged as alternatives to surgical aortic valve replacement in certain patient populations. Additionally, non-surgical treatment options have expanded for conditions affecting other cardiac valves, such as the mitral valve. These emerging minimally invasive interventions complement already well-established endovascular techniques for, among others, atrial septal defect closure, left atrial appendage occlusion and pulmonary vein isolation in patients with atrial fibrillation. Given their non-surgical nature and lack of direct visualisation of the targeted anatomy, these procedures heavily rely on precise pre-procedural radiological imaging for optimal patient selection and procedural success. Method: This paper is based on the expert opinion of the authors and an exhaustive literature research. Results: This manuscript reviews the most commonly employed minimally invasive cardiac interventions, highlighting the essential pre-procedural imaging information and key aspects that must be included in radiological reports to mitigate potential complications. Conclusion: Accurate pre-procedural imaging is crucial for ensuring safe and effective minimally invasive cardiac interventions, underscoring the importance of the radiologist in the pre-procedural work-up of these patients.

Tricuspid Regurgitation in the Setting of Cardiac Implantable Electronic Devices

Cardiac implantable electronic devices (CIEDs) have been increasingly used in the management of various rhythm disorders amidst an aging population with more prevalent cardiovascular comorbidities. Although generally well-tolerated and safe, implantation of CIEDs may result in or worsen tricuspid regurgitation (TR), which is associated with a higher risk of morbidity and mortality. Several mechanisms of TR following device implantation have been proposed, and multiple diagnostic tests, percutaneous and surgical interventions, and alternative pacing methods have been developed to address this. CIED-related TR thus requires a multidisciplinary team of experts in cardiac imaging, interventional cardiology, electrophysiology, and cardiothoracic surgery with a comprehensive understanding of this multifaceted disease. The objective of this review is to summarize the epidemiology, clinical presentation, and management of CIED-related TR.

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.

Multimodality Imaging for Right Ventricular Function Assessment in Severe Tricuspid Regurgitation

Severe tricuspid regurgitation (TR) is a pathological condition associated with worse cardiovascular outcomes. In the vicious cycle of right ventricular compensation and maladaptation to TR, the development of right ventricle (RV) dysfunction has significant prognostic implications, especially in patients undergoing surgical or percutaneous treatments. Indeed, RV dysfunction is associated with increased operative morbidity and mortality in both surgical and percutaneously treated patients. In this context, the identification of clinical or subtle right ventricle dysfunction plays a critical role inpatient selection and timing of surgical or percutaneous tricuspid valve intervention. However, in the presence of severe TR, evaluation of RV function is challenging, given the increase in preload that may lead to an overestimation of systolic function for the Frank-Starling law, reduced reliability of pulmonary artery pressure estimation, the sensitivity of RV to afterload that may result in afterload mismatch after treatment. Consequently, conventional echocardiographic indices have some limitations, and the use of speckle tracking for right ventricular free wall longitudinal strain (RV-FWLS) analysis and the use of 3D echocardiography for RV volumes and ejection fraction estimation are showing promising data. Cardiac magnetic resonance (CMR) represents the gold standards for volumes and ejection fraction evaluation and may add further prognostic information. Finally, cardiac computer tomography (CCT) provides measurements of RV and annulus dimensions that are particularly useful in the transcatheter field. Identification of subtle RV dysfunction may need, therefore, more than one imaging technique, which will lead to tip the balance between medical therapy and early intervention towards the latter before disease progression. Therefore, the aim of this review is to describe the main imaging techniques, providing a comprehensive assessment of their role in RV function evaluation in the presence of severe TR.

Predictors of residual tricuspid regurgitation after interventional therapy: an automated deep-learning CT analysis

Computed tomography (CT) is used as a valuable tool for device selection for interventional therapy in tricuspid regurgitation (TR). We aimed to evaluate predictors of TR reduction using CT and automated deep learning algorithms. Patients with severe to torrential TR and CTs prior to either percutaneous annuloplasty (PA) or tricuspid transcatheter edge-to-edge repair (T-TEER) were enrolled. CTs were analyzed using automated deep learning algorithms to assess tricuspid valve anatomy, right heart morphology, and function. Outcome parameters comprised post-interventional TR ≤ 1 and all-cause mortality. 84 patients with T-TEER (n = 32) or PA treatment (n = 52) were enrolled. Patients with a post-interventional TR ≤ 1 presented lower tenting heights and smaller tenting angles compared to patients with a TR > 1. Tenting height showed the best accuracy for post-interventional TR > 1 with an AUC of 0.756 (95% CI 0.560-0.951) in the T-TEER and 0.658 (95% CI 0.501-0.815) in the PA group, consistent with a suggested threshold of 6.8 mm and 9.2 mm, respectively. Patients with a post-interventional TR ≤ 1 exhibited a mortality of 4% and those with a TR > 1 of 12% during a follow-up of 331 ± 300 and 370 ± 265 days, respectively (p = 0.124). To conclude, tenting is associated with procedural outcomes and should be considered during screening for interventional TR therapy.

The Diagnosis and Treatment of Tricuspid Regurgitation

BACKGROUND

It is estimated that 6% of persons over age 75 have clinically relevant tricuspid regurgitation (TR). This condition carries a high mortality and is of particular interest because of the recent development of new interventional treatments.

METHODS

This review is based on publications that were retrieved by a selective search in the PubMed database for randomized controlled trials (RCTs), observational studies, registry studies, expert recommendations, and current international guidelines.

RESULTS

The evidence reveals that TR is an independent cause of mortality. Mortality is correlated with the severity of TR: approximately 35% of patients with severe TR and right heart failure die within 1 year, and about 60% within 3 years. The clinical course varies depending on the etiology (primary TR, atrial/ventricular secondary TR, association with pacemaker systems). In the outpatient setting, timely diagnosis by transthoracic echocardiography is crucial. The options for pharmacotherapy are essentially limited to diuretic treatment (grade 2a recommendation). Early referral to a specialized heart valve center is essential for the prevention of irreversible damage of the right heart and secondary end-organ damage, including cardiohepatic and cardiorenal syndromes. In the heart valve center, an extended diagnostic evaluation with multimodal imaging is followed by a case discussion by the interdisciplinary cardiac team, with individual evaluation of the treatment options. The first randomized controlled trial of treatment for TR yielded a win ratio of 1.48 (95% confidence interval, [1.06; 2.13]) for interventional treatment (edge-to-edge repair) compared to optimal medical therapy.

CONCLUSION

As the understanding of tricuspid regurgitation improves, strategies for its interventional treatment are undergoing steady development, with the aim of lowering the mortality of this condition.

New Therapeutic Advances in the Management of Tricuspid Valve Regurgitation

Tricuspid regurgitation (TR) is an intricate disorder that has a negative outlook, while surgical treatment is linked to increased mortality. Primary TR occurs due to a structural defect in the tricuspid valve (TV), while secondary TR is a more prevalent condition often associated with pulmonary hypertension, heart failure, and atrial fibrillation. The use of specific surgical procedures to improve TR is limited in everyday clinical practice due to the heightened surgical risk and delayed patient presentation. The development of other transcatheter heart valve procedures has led to a significant increase in transcatheter TV operations, which can be attributed to certain technological advancements. This review aims to provide an updated overview of transcatheter TV procedures, available alternative therapies, and standards for patient selection. It will also highlight the current state of development in this field, which is characterized by rapid progress and numerous ongoing clinical trials.

[Role of computed tomography in transcatheter coronary and structural heart disease interventions]

Computed tomography is a noninvasive imaging technique with high spatial resolution, providing excellent definition of calcium and intravascular space through the use of contrast media. This imaging modality allows both highly accurate measurements and virtual simulations for preprocedural planning in coronary and structural heart disease interventions. Computed tomography is currently the gold standard technique for patient selection and preprocedural planning in numerous scenarios, such as transcatheter aortic valve implantation, left atrial appendage occlusion, transcatheter mitral valve repair, and transcatheter tricuspid valve repair. This article reviews the role of computed tomography in transcatheter coronary and structural heart disease interventions.

Computed tomography imaging in preprocedural planning of transcatheter valvular heart interventions

Cardiac Computed Tomography (CCT) has become a reliable imaging modality in cardiology providing robust information on the morphology and structure of the heart with high temporal and isotropic spatial resolution. For the past decade, there has been a paradigm shift in the management of valvular heart disease since previously unfavorable candidates for surgery are now provided with less-invasive interventions. Transcatheter heart valve interventions provide a real alternative to medical and surgical management and are often the only treatment option for valvular heart disease patients. Successful transcatheter valve interventions rely on comprehensive multimodality imaging assessment. CCT is the mainstay imaging technique for preprocedural planning of these interventions. CCT is critical in guiding patient selection, choice of procedural access, device selection, procedural guidance, as well as allowing postprocedural follow-up of complications. This article aims to review the current evidence of the role of CCT in the preprocedural planning of patients undergoing transcatheter valvular interventions.

The Tricuspid Valve: A Review of Pathology, Imaging, and Current Treatment Options: A Scientific Statement From the American Heart Association

Tricuspid valve disease is an often underrecognized clinical problem that is associated with significant morbidity and mortality. Unfortunately, patients will often present late in their disease course with severe right-sided heart failure, pulmonary hypertension, and life-limiting symptoms that have few durable treatment options. Traditionally, the only treatment for tricuspid valve disease has been medical therapy or surgery; however, there have been increasing interest and success with the use of transcatheter tricuspid valve therapies over the past several years to treat patients with previously limited therapeutic options. The tricuspid valve is complex anatomically, lying adjacent to important anatomic structures such as the right coronary artery and the atrioventricular node, and is the passageway for permanent pacemaker leads into the right ventricle. In addition, the mechanism of tricuspid pathology varies widely between patients, which can be due to primary, secondary, or a combination of causes, meaning that it is not possible for 1 type of device to be suitable for treatment of all cases of tricuspid valve disease. To best visualize the pathology, several modalities of advanced cardiac imaging are often required, including transthoracic echocardiography, transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging, to best visualize the pathology. This detailed imaging provides important information for choosing the ideal transcatheter treatment options for patients with tricuspid valve disease, taking into account the need for the lifetime management of the patient. This review highlights the important background, anatomic considerations, therapeutic options, and future directions with regard to treatment of tricuspid valve disease.

[Clinical aspects and treatment of tricuspid valve regurgitation]

Tricuspid regurgitation (TR) leading to right heart failure is prevalent and associated with increased mortality. The significant under-recognition of the disease resulted from insufficient medical therapies and the high associated risk of surgical therapy. Over the last decade there has been a rapid development of interventional treatment options so that the disease has increasingly become the focus of attention of specialists in internal medicine and interventional cardiologists. The etiology of TR is differentiated into primary TR, secondary atrial TR, secondary ventricular TR and TR associated with cardiac implantable electronic devices (CIED). The TR was identified as an independent predictor of mortality, independent of associated diseases such as atrial fibrillation, left-sided heart failure or pulmonary hypertension. Even patients with low to moderate TR have a significantly increased risk of mortality. Early diagnostics and estimation of the severity by echocardiography as well as timely referral to a tertiary heart valve center are decisive in order to evaluate possible treatment options before irreversible right ventricular damage and secondary organ dysfunction occur. For transcatheter edge-to-edge repair and transcatheter tricuspid valve replacement there is now first evidence from randomized controlled studies. While the understanding of TR is continuously improving, new tricuspid valve repair and replacement systems are in a state of steady progress. Whether the treatment has an effect on reduction of the mortality and stabilization of right ventricular failure with a reduction in hospitalization, will first be shown in future studies.

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.

Device innovation in cardiovascular medicine: a report from the European Society of Cardiology Cardiovascular Round Table

Research performed in Europe has driven cardiovascular device innovation. This includes, but is not limited to, percutaneous coronary intervention, cardiac imaging, transcatheter heart valve implantation, and device therapy of cardiac arrhythmias and heart failure. An important part of future medical progress involves the evolution of medical technology and the ongoing development of artificial intelligence and machine learning. There is a need to foster an environment conducive to medical technology development and validation so that Europe can continue to play a major role in device innovation while providing high standards of safety. This paper summarizes viewpoints on the topic of device innovation in cardiovascular medicine at the European Society of Cardiology Cardiovascular Round Table, a strategic forum for high-level dialogue to discuss issues related to the future of cardiovascular health in Europe. Devices are developed and improved through an iterative process throughout their lifecycle. Early feasibility studies demonstrate proof of concept and help to optimize the design of a device. If successful, this should ideally be followed by randomized clinical trials comparing novel devices vs. accepted standards of care when available and the collection of post-market real-world evidence through registries. Unfortunately, standardized procedures for feasibility studies across various device categories have not yet been implemented in Europe. Cardiovascular imaging can be used to diagnose and characterize patients for interventions to improve procedural results and to monitor devices long term after implantation. Randomized clinical trials often use cardiac imaging-based inclusion criteria, while less frequently trials randomize patients to compare the diagnostic or prognostic value of different modalities. Applications using machine learning are increasingly important, but specific regulatory standards and pathways remain in development in both Europe and the USA. Standards are also needed for smart devices and digital technologies that support device-driven biomonitoring. Changes in device regulation introduced by the European Union aim to improve clinical evidence, transparency, and safety, but they may impact the speed of innovation, access, and availability. Device development programmes including dialogue on unmet needs and advice on study designs must be driven by a community of physicians, trialists, patients, regulators, payers, and industry to ensure that patients have access to innovative care.

Contemporary Approach to Tricuspid Regurgitation: Knowns, Unknowns, and Future Challenges

Severe tricuspid regurgitation (TR) worsens heart failure and is associated with impaired survival. In daily clinical practice, patients are referred late, and tricuspid valve interventions (surgical or transcatheter) are underutilised, which may lead to irreversible right ventricular damage and increases risk. This article addresses the appropriate timing and modality for an intervention (surgical or transcatheter), and its potential benefits on clinical outcomes. Ongoing randomised controlled trials will provide further insights into the efficacy of transcatheter valve interventions compared with medical treatment.

Tricuspid valve disease and cardiac implantable electronic devices

The role of cardiac implantable electronic device (CIED)-related tricuspid regurgitation (TR) is increasingly recognized as an independent clinical entity. Hence, interventional TR treatment options continuously evolve, surgical risk assessment and peri-operative care improve the management of CIED-related TR, and the role of lead extraction is of high interest. Furthermore, novel surgical and interventional tricuspid valve treatment options are increasingly applied to patients suffering from TR associated with or related to CIEDs. This multidisciplinary review article developed with electrophysiologists, interventional cardiologists, imaging specialists, and cardiac surgeons aims to give an overview of the mechanisms of disease, diagnostics, and proposes treatment algorithms of patients suffering from TR associated with CIED lead(s) or leadless pacemakers.

Cardiac CT Beyond Coronaries: Focus on Structural Heart Disease

PURPOSE OF REVIEW

Cardiac computed tomography (CT) is an established non-invasive imaging tool for the assessment of coronary artery disease. Furthermore, it plays a key role in the preinterventional work-up of patients presenting with structural heart disease.

RECENT FINDINGS

CT is the gold standard for preprocedural annular assessment, device sizing, risk determination of annular injury, coronary occlusion or left ventricular outflow tract obstruction, calcification visualization and quantification of the target structure, and prediction of a co-planar fluoroscopic angulation for transcatheter interventions in patients with structural heart disease. It is further a key imaging modality in postprocedural assessment for prosthesis thrombosis, degeneration, or endocarditis. CT plays an integral part in the imaging work-up of novel transcatheter therapies for structural heart disease and postprocedural assessment for prosthesis thrombosis or endocarditis. This review provides a comprehensive overview of the key role of CT in the context of structural heart interventions.

30-Day Outcomes of Transcatheter Tricuspid Annuloplasty With the K-Clip System: A Single-Center, Observational Study

Background

Surgery for isolated functional tricuspid regurgitation (TR) poses a high risk. Several transcatheter approaches are being evaluated for the treatment of such patients. The K-Clip system is a percutaneous approach designed for functional TR; however, its utility remains unknown.

Objectives

This study aimed to report the 30-day echocardiographic and clinical outcomes with the K-Clip system for severe TR, including changes in TR severity and NYHA functional class.

Methods

Transcatheter tricuspid valve annuloplasty was performed in 39 patients with intermediate or high surgical risk who underwent the K-Clip system. The right internal jugular vein procedure was performed with annuloplasty guided by fluoroscopy and echocardiography. The primary outcomes were clinical success and all-cause mortality at the 30-day follow-up.

Results

The K-Clip was successfully implanted in all cases, with 1 to 3 devices deployed. At the 30-day follow-up, none of the patients had died. TR severity was reduced by at least one grade in all patients. There were no severe procedural or 30-day adverse events, except for 1 new pacemaker implantation. The proportion of NYHA class III-IV patients decreased from 79.5% to 5.1%, and the ascites disappeared. The 6-minute walk distance increased by 78 m (P < 0.05), and the Kansas City Cardiomyopathy Questionnaire score improved by 11 points (P < 0.05).

Conclusions

The K-Clip device is practical, safe, and effective for patients with severe TR. A 30-day reduction in TR and enhanced cardiac function and quality of life were associated with transcatheter tricuspid annuloplasty using the K-Clip device, according to short-term follow-up studies. (Confirmatory Clinical Study of Treating Tricuspid Regurgitation With K-Clip TM Transcatheter Annuloplasty System [TriStar]; NCT05173233).

Unmet Needs in the Assessment of Right Ventricular Function for Severe Tricuspid Regurgitation

Tricuspid regurgitation (TR) is a highly prevalent valvular heart disease that has been long overlooked, but lately its independent association with adverse cardiovascular outcomes was recognized. The time point to intervene and repair the tricuspid valve is defined by the right ventricular (RV) dilation and dysfunction that comes up at a later stage. While guidelines favor tricuspid valve repair before severe RV dysfunction ensues, the definition of RV dysfunction in a universal manner remains vague. As a result, the candidates for transcatheter or surgical TR procedures are often referred late, when advanced RV dysfunction is established, and any derived procedural survival benefit is attenuated. Thus, it is of paramount importance to establish a universal means of RV function assessment in patients with TR. Conventional echocardiographic indices of RV function routinely applied have fundamental flaws that limit the precise characterization of RV performance. More recently, novel echocardiographic indices such as strain via speckle-tracking have emerged, demonstrating promising results in the identification of early RV damage. Additionally, evidence of the role of alternative imaging modalities such as cardiac computed tomography and cardiac magnetic resonance, for RV functional assessment in TR, has recently arisen. This review provides a systematic appraisal of traditional and novel multimodality indices of RV function in severe TR and aims to refine RV function assessment, designate future directions, and ultimately, to improve the outcome of patients suffering from severe TR.

Human fitting of pediatric and infant continuous-flow total artificial heart: visual and virtual assessment

Background

This study aimed to determine the fit of two small-sized (pediatric and infant) continuous-flow total artificial heart pumps (CFTAHs) in congenital heart surgery patients.

Methods

This study was approved by Cleveland Clinic Institutional Review Board. Pediatric cardiac surgery patients (n = 40) were evaluated for anatomical and virtual device fitting (3D-printed models of pediatric [P-CFTAH] and infant [I-CFTAH] models). The virtual sub-study consisted of analysis of preoperative thoracic radiographs and computed tomography (n = 3; 4.2, 5.3, and 10.2 kg) imaging data.

Results

P-CFTAH pump fit in 21 out of 40 patients (fit group, 52.5%) but did not fit in 19 patients (non-fit group, 47.5%). I-CFTAH pump fit all of the 33 patients evaluated. There were critical differences due to dimensional variation (p < 0.0001) for the P-CFTAH, such as body weight (BW), height (Ht), and body surface area (BSA). The cutoff values were: BW: 5.71 kg, Ht: 59.0 cm, BSA: 0.31 m². These cutoff values were additionally confirmed to be optimal by CT imaging.

Conclusions

This study demonstrated the range of proper fit for the P-CFTAH and I-CFTAH in congenital heart disease patients. These data suggest the feasibility of both devices for fit in the small-patient population.

Functional Mitral and Tricuspid Regurgitation across the Whole Spectrum of Left Ventricular Ejection Fraction: Recognizing the Elephant in the Room of Heart Failure

Functional mitral regurgitation (FMR) and tricuspid regurgitation (FTR) occur due to cardiac remodeling in the presence of structurally normal valve apparatus. Two main mechanisms are involved, distinguishing an atrial functional form (when annulus dilatation is predominant) and a ventricular form (when ventricular remodeling and dysfunction predominate). Both affect the prognosis of patients with heart failure (HF) across the entire spectrum of left ventricle ejection fraction (LVEF), including preserved (HFpEF), mildly reduced (HFmrEF), or reduced (HFrEF). Currently, data on the management of functional valve regurgitation in the various HF phenotypes are limited. This review summarizes the epidemiology, pathophysiology, and treatment of FMR and FTR within the different patterns of HF, as defined by LVEF.

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.

Evolving computed tomography angiography for aortic valve replacement: Optimizing transcatheter and surgical therapies

Transcatheter aortic valve replacement (TAVR) has transformed the treatment of aortic stenosis and pre-procedure planning relies heavily on advanced imaging. Multidetector computed tomography angiography, the "TAVR CT," facilitates essential planning steps of measuring the aortic root for valve sizing and feasibility and assessment of potential access vessels, making it the guideline gold standard in preprocedural TAVR work up. This Impact of Advanced Imaging Techniques on Cardiac Surgery article will examine the development of TAVR CT, illustrate the current impact and utility, and highlight potential areas of future growth. Clinicians who keep informed of these changes and can become proficient with TAVR CT analyses will offer patients the most optimal results and fuel future therapeutic growth.

CT in Transcatheter-delivered Treatment of Valvular Heart Disease

Minimally invasive strategies to treat valvular heart disease have emerged over the past 2 decades. The use of transcatheter aortic valve replacement in the treatment of severe aortic stenosis, for example, has recently expanded from high- to low-risk patients and became an alternative treatment for those with prohibitive surgical risk. With the increase in transcatheter strategies, multimodality imaging, including echocardiography, CT, fluoroscopy, and cardiac MRI, are used. Strategies for preprocedural imaging strategies vary depending on the targeted valve. Herein, an overview of preprocedural imaging strategies and their postprocessing approaches is provided, with a focus on CT. Transcatheter aortic valve replacement is reviewed, as well as less established minimally invasive treatments of the mitral and tricuspid valves. In addition, device-specific details and the goals of CT imaging are discussed. Future imaging developments, such as peri-procedural fusion imaging, machine learning for image processing, and mixed reality applications, are presented.

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.

Atrial Functional Tricuspid Regurgitation as a Distinct Pathophysiological and Clinical Entity: No Idiopathic Tricuspid Regurgitation Anymore

Functional tricuspid regurgitation (FTR) is a strong and independent predictor of patient morbidity and mortality if left untreated. The development of transcatheter procedures to either repair or replace the tricuspid valve (TV) has fueled the interest in the pathophysiology, severity assessment, and clinical consequences of FTR. FTR has been considered to be secondary to tricuspid annulus (TA) dilation and leaflet tethering, associated to right ventricular (RV) dilation and/or dysfunction (the "classical", ventricular form of FTR, V-FTR) for a long time. Atrial FTR (A-FTR) has recently emerged as a distinct pathophysiological entity. A-FTR typically occurs in patients with persistent/permanent atrial fibrillation, in whom an imbalance between the TA and leaflet areas results in leaflets malcoaptation, associated with the dilation and loss of the sphincter-like function of the TA, due to right atrium enlargement and dysfunction. According to its distinct pathophysiology, A-FTR poses different needs of clinical management, and the various interventional treatment options will likely have different outcomes than in V-FTR patients. This review aims to provide an insight into the anatomy of the TV, and the distinct pathophysiology of A-FTR, which are key concepts to understanding the objectives of therapy, the choice of transcatheter TV interventions, and to properly use pre-, intra-, and post-procedural imaging.

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.

Right Heart Morphology of Candidate Patients for Transcatheter Tricuspid Valve Interventions

Purpose

This study quantitatively evaluated the phasic right heart morphology of candidate patients for a transcatheter tricuspid valve intervention (N=32) and of subjects with trace to no tricuspid regurgitation (N = 14).

Methods

Cardiac computed tomography angiography (CCTA) and transthoracic/transesophageal echocardiography (TTE/TEE) images were analyzed using dedicated research and clinical software. Using CCTA, the phasic right atrial and ventricular volumes, annulus dimensions, annulus-to-right coronary artery (RCA) distances, circumferential topography of the annular tissue shelf, vena cava dimensions (inferior and superior), vena cava positions, axis angles, and annular excursions were quantified. Using TTE/TEE, leaflet geometry, regurgitation, hemodynamics, and heart function were quantified. Measurements within and between groups were quantitatively compared with regression analyses to explore relationships between right heart features.

Results

The phasic position and orientation of the vena cava and the circumferential topography of the annular tissue shelf were quantitatively presented for the first time. The candidate patient group exhibited greater chamber dimensions, enlarged vena cava, distended vena cava positions, positional shallowing of the annular tissue shelf, geometric annular distortion, leaflet distention, moderate or greater regurgitation, and impaired ventricular function. Atrial volume correlated strongly with directional vena cava positions as well as with annular dimensions. Annulus-to-RCA distances and annular excursions were comparable between groups.

Conclusions

This study provides new and further insight to the right heart morphology and functional characteristics of candidate patients for a transcatheter tricuspid valve intervention. These data provide a platform from which these patients can continue to be better understood for further improving transcatheter system design and use.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13239-021-00595-y.

Roles of Cardiac Computed Tomography in Guiding Transcatheter Tricuspid Valve Interventions

PURPOSE OF REVIEW

The field of transcatheter tricuspid valve interventions (TTVI) is rapidly evolving to meet a well-defined but unmet clinical need. Severe tricuspid regurgitation is common and is associated with significant morbidity and mortality. Surgical options are limited and of high risk. The success of TTVI depends on careful procedural planning, and cardiac computed tomography (CCT) plays an emerging key role.

RECENT FINDINGS

TTVI technologies have various targets, including the leaflets, annulus, and venae cavae, along with valve replacement. Based on the planned procedure, CCT allows for device sizing, careful assessment of the access route, and comprehensive analysis of relevant adjacent anatomic structures to enhance procedural safety. It can also evaluate right-sided heart function, and its data can be for fusion imaging and 3D printing. Procedural planning is key to TTVI's success and is highly dependent on high-quality CCT data. This review details the comprehensive roles of CCT, specifics of the dedicated TTVI protocol, and its limitations.

2020: Entwicklungen in der kardialen Computertomographie

Die Entwicklung der kardialen Computertomographie (CT) im Jahr 2020 war durch 3 dominante Schwerpunkte im Bereich der koronaren Bildgebung gekennzeichnet: 1) die prognostische Bedeutung der Plaquebildung, 2) die Möglichkeit ihrer volumetrischen Quantifizierung und 3) den Bedeutungsgewinn in den Leitlinien, verstärkt durch die zunehmende Anwendung in der Therapie von strukturellen Herzerkrankungen. Die Veröffentlichung der Ergebnisse von ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) hat den Blick auf die anatomische Charakterisierung der koronaren Herzkrankheit gelenkt, die Visualisierung der koronaren Plaquebildung. Nicht zuletzt als Ergebnis von „machine learning“/künstlicher Intelligenz hat sich die Möglichkeit herauskristallisiert, die koronare Plaquebildung automatisiert und volumetrisch zu erfassen. Diese beiden Entwicklungen haben die Frage nach der prognostischen Dominanz des Ischämienachweises aufgeworfen, der sekundär aus der Plaquebildung resultiert. Auch hat sich das Verständnis der Pathophysiologie der koronaren Herzerkrankung verändert: Die Ausprägung des (nicht verkalkten) Plaquevolumens, seine Lokalisierung und Dynamik scheinen als Merkmale der Vulnerabilität im Vergleich zur Fokussierung auf ein großes Atherom oder expansives Remodeling einzelner Plaques bedeutsamer zu sein. In den Leitlinien ist die koronare CT-Angiographie (CTA) sowohl bei den akuten Koronarsyndromen ohne ST-Hebung als auch den chronischen Koronarsyndromen an die erste Stelle gerückt – gleichberechtigt mit den klassischen bildgebenden Ischämietests. Unabhängig davon gewinnt die kardiale CT zunehmend an Bedeutung für die Therapieplanung von Vitien (insbesondere der Aorten- und Trikuspidalklappe), aber auch anderer struktureller Herzerkrankungen (z. B. Verschluss des linken Vorhofohrs, LAA).