Transatrial intrapericardial tricuspid annuloplasty

Transcatheter tricuspid valve interventions: Current devices and clinical evidence

The tricuspid valve is known as "the forgotten valve". Tricuspid regurgitation (TR) is a highly prevalent valvular heart disease. TR is often late in the course of the disease when it becomes symptomatic, often being a marker of late-stage chronic heart failure with a poor prognosis and high mortality rate at long-term follow-up. Despite the clear correlation between TR and mortality, most TR patients are under-treated. Neither pharmacologic nor surgical treatment demonstrates a significant survival benefit. Isolated tricuspid valve surgery has the highest mortality rate of all valve surgeries. Therefore, there is an urgent clinical need for minimally invasive therapies to meet the needs of patients with TR. In recent years, a variety of transcatheter tricuspid valve interventions representing less invasive alternatives to surgery have shown promising results, which bring hope to patients with severe TR. The purpose of this review is to provide a complete and updated overview on current transcatheter tricuspid valve interventions and clinical evidence.

Transcatheter Intervention for Management of Tricuspid Regurgitation Using TriClip

Severe tricuspid regurgitation (TR) is an underrated, common pathology that affects over 70 million individuals worldwide. Traditionally, TR has been managed with diuretic therapies without any significant mortality benefit. The underlying cause of TR can be primary, coming from structural issues with tricuspid valve and more commonly secondary, arising from conditions affecting the right ventricle or the pulmonary circulation. Management of TR has seen few improvements until recently. Traditionally, valve replacement and surgical repair were the therapeutic options available. Tricuspid valve is a complex cardiac structure with many technical challenges for surgical intervention. Transcatheter valve interventions have proven to be safe and effective novel therapeutic options for severe TR, which reduce the severity of TR with associated improvement in quality of life. In this review, we will provide an overview of the management of severe TR utilizing transcatheter edge-to-edge repair with the TriClip device (Abbott, Santa Clara, CA).

Utility of CT and MRI in Tricuspid Valve Interventions

Transcatheter tricuspid valve interventions (TTVIs) comprise a variety of catheter-based interventional techniques for treatment of tricuspid regurgitation (TR) in patients at high surgical risk and those with failed previous surgeries. Several TTVI devices with different mechanisms of action are either currently used or in preclinical evaluation. Echocardiography is the first-line modality for evaluation of tricuspid valve disease that provides information on tricuspid valve morphology, mechanism of TR, and hemodynamics. Cardiac CT and MRI have several advantages for a comprehensive preprocedure evaluation. CT and MRI provide complementary information to that of echocardiography on the mechanism and cause of TR. MRI can quantify the severity of TR using indirect or direct techniques that involve two-dimensional or four-dimensional flow sequences. MRI and CT can also accurately quantify right ventricular volumes and function, which is crucial for timing of intervention. CT provides comprehensive three-dimensional information on the morphology of the valve, annulus, subvalvular apparatus, and adjacent structures. CT is the procedure of choice for evaluation of several device-specific measurements, including tricuspid annulus dimensions, annulus-to-right coronary artery distance, leaflet morphology, coaptation gaps, caval dimensions, and cavoatrial-to-hepatic vein distance. CT allows evaluation of the vascular access as well as optimal procedure fluoroscopic angles and catheter trajectory. Postprocedure CT and MRI are useful in detection of complications such as paravalvular leak, pseudoaneurysm, thrombus, pannus, infective endocarditis, and device migration. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

New therapeutic approach for tricuspid regurgitation: Transcatheter tricuspid valve replacement or repair

The tricuspid valve is a complex structure with normal function dependent on the leaflet morphology, right atrial and annular dynamics, and right ventricular and chordal support. Thus, the pathophysiology of tricuspid regurgitation (TR) is equally complex and current medical and surgical management options are limited. Transcatheter devices are currently being investigated as possible treatment options with lower morbidity and mortality than open surgical procedures. These devices can be divided by their implant location/mechanism of action: leaflet approximation devices, annuloplasty devices, orthotopic valve implants, and heterotopic valve implants. The current review will discuss each class of transcatheter device therapy, and further delve into the current understanding of who and when to treat. Finally, we will include a brief discussion of the future of device and surgical therapy trials for TR and the remaining questions to answer about this complex disease process.

Transcatheter tricuspid valve interventions: Current status and future perspectives

The development of transcatheter therapies to treat valvular heart diseases has changed the rules of the game, particularly in the case of aortic stenosis and mitral regurgitation. In the last years, the tricuspid valve has also been the focus of these percutaneous techniques for several reasons: (1) tricuspid regurgitation is a frequent disease associated with poor clinical outcomes in spite of medical treatment, leading to end-stage right ventricular heart failure, (2) surgical tricuspid valve repair or replacement has been the treatment of choice for patients with tricuspid valve disease, but high mortality rates for isolated surgical tricuspid valve intervention have been reported in the literature, and (3) most patients with tricuspid pathology are ultimately denied cardiac surgery because of their comorbidity burden. Thus, in this context the development of less invasive catheter-based therapies would be of high clinical relevance. The present review provides an overview regarding the framework of chronic tricuspid regurgitation transcatheter therapeutic options, summarizes the transcatheter systems under clinical use or clinical evaluation with their technical features, and describes the updated current evidence in this challenging and evolving field.

Transcatheter interventions for severe tricuspid regurgitation: a literature review

The prevalence of tricuspid regurgitation (TR) increases with age, affecting 65%-85% of adults. Primary TR is caused by a congenital or acquired abnormality of the tricuspid valve apparatus (leaflets, chordae, papillary muscles, or annulus). Secondary TR is due to insufficient coaptation from dilation of tricuspid valve annulus due to the right ventricle (RV) or right atrium (RA) remodeling and increased RV pressures. Isolated TR is without increased RV pressures and is associated with atrial fibrillation. Mild TR is a benign disease. Moderate to severe tricuspid regurgitation has independently been associated with increased mortality. Most of these patients are treated medically due to poor outcomes with surgical repair of isolated TR. The in-hospital mortality rate is 8.8%, and the median length of stay in hospital is 11 days resulting in higher healthcare costs. Even if the patients undergo surgical repair or replacement, available data do not show improvement in survival. With a more detailed understanding of the complex anatomy and physiology of the tricuspid valve and significant complications from untreated tricuspid valve disease, the approach to the management of TR has shifted from a conservative approach to a process of prevention and intervention. In the past decade, transcatheter tricuspid valve interventions and tricuspid annuloplasty rings have been developed, contributing to decreased mortality from surgical repair. Transcatheter tricuspid valve intervention techniques have improved survival, quality of life, and reduced heart failure rehospitalization. This review summarizes normal anatomy, types of TR, etiology and different mechanisms of TR, echocardiographic assessment of the severe TR, and highlights various percutaneous transcatheter techniques for tricuspid valve repair.

Tricuspid Valve Percutaneous Therapies

PURPOSE OF REVIEW

In this review, we have focused on the currently available transcatheter tricuspid valve therapies, device selection, as well as role and management of tricuspid regurgitation (TR) in the setting of other transcatheter valvular procedures.

RECENT FINDINGS

In this review, we have enlisted the recently finished as well as ongoing trials in the percutaneous tricuspid valve therapies. TR is highly prevalent yet remains underrecognized and is often untreated. TR has traditionally been managed conservatively with medical therapies including diuretics for volume management, whereas surgical therapies are reserved for those undergoing left-sided valvular surgery. Although the transcatheter devices for tricuspid repair and replacement are in clinical trials, the experience to date for their effectiveness and safety has been reassuring.

Current Status of Transcatheter Tricuspid Valve Therapies

Tricuspid regurgitation is a complex disease that carries a poor prognosis, and surgical repair is associated with high mortality. In light of the success of other transcatheter-based valve interventions, transcatheter tricuspid therapy has recently seen exponential use both clinically and in innovation. Given the rapid development of many tricuspid systems and multiple on-going clinical trials, the aim of this review is to highlight the current state of transcatheter tricuspid therapeutics and to provide an up-to-date view of their clinical use, outcomes and future directions.

Multi-Modality Imaging of the Tricuspid Valve: From Tricuspid Valve Disease to Catheter-Based Interventions

Tricuspid valve disease represents a major health problem that affects a wide proportion of heart failure patients with a significant prognostic impact. In recent years an increasing number of minimally invasive and transcatheter treatments have been developed. The choice of the optimal transcatheter device therapy needs a careful patient selection and a dedicated anatomic assessment, mainly based on echocardiographic and computed tomography evaluation. Moreover, cardiac magnetic resonance has an established role in the functional assessment of right heart chambers with relevant prognostic implications. In this review we describe the role of multimodality imaging in the tricuspid valve disease assessment with an intervention-oriented perspective, from the pre-operative planning for different devices to the intraprocedural guide during transcatheter edge-to-edge repair.

Transcatheter Annular Approaches for Tricuspid Regurgitation (Cardioband and Others)

The tricuspid valve often is referred to as "the forgotten valve" because it frequently is managed conservatively due to poor prognostic outcomes with conventional surgical intervention, in particular, in high-risk patients. Nevertheless, a paradigm shift has occurred in recent years, due to a growing evidence base supporting the independent prognostic influence of severe tricuspid regurgitation (TR) on patient outcomes. Both transcatheter valve replacement and valve repair have emerged as feasible and efficacious interventions for TR correction. Novel transcatheter repair techniques that replicate surgical annuloplasty are evolving as potentially lower-risk alternatives.

Transcatheter tricuspid valve interventions: Current devices and associated evidence

Tricuspid regurgitation (TR) is a common finding in patients with chronic cardiopathy, and often a marker of an advanced disease. Being silent or with symptoms intertwined with the primitive left heart disease, TR has often been neglected, leading to the late referral of patients with advanced right-heart failure. Hence, isolated tricuspid surgery has been associated with high morbidity and mortality rates, the worse of all valve interventions, and medical management has been limited to symptomatic treatment. In this context, percutaneous therapies for severe TR have gained traction, addressing the unmet therapeutic gap for a less invasive disease-modifying management. The aim of this review is to provide an updated overview on transcatheter tricuspid valve interventions, focusing on devices' characteristics, associated evidence, and future perspectives.

[Current technologies in interventional treatment of tricuspid valve regurgitation]

For a long time, severe tricuspid valve regurgitation (TR) was an underestimated disease, especially in the older population and was associated with high morbidity and mortality. Due to the high perioperative mortality of tricuspid valve surgery, historically only pharmaceutical treatment was a practical treatment option. In the first studies interventional approaches could achieve promising results with an effective reduction of TR with simultaneous proof of a convincing safety profile. Conceptually, the currently available interventional treatment options can be divided into three concepts: coaptation systems (edge-to-edge repair), annuloplasty and interventional valve replacement. The largest clinical experience and best scientific body of evidence could so far be generated in the field of coaptation systems. Very promising preliminary results with effective reduction of TR and improvement of the clinical symptoms are, however, also available for interventional valve replacement. Meticulous preprocedural diagnostics with selection of the most suitable treatment option for each individual patient is paramount for successful treatment in this critically ill patient cohort. Future prospective randomized studies will investigate the net benefit of an interventional treatment of TR in comparison to a purely conservative treatment concept.

Transcatheter tricuspid valve repair and replacement: a landscape review of current techniques and devices for the treatment of tricuspid valve regurgitation

Background and ObjectiveTricuspid regurgitation is a prevalent and undertreated cardiac pathology impacting millions across the globe. While historically surgical interventions for isolated tricuspid regurgitation were largely avoided due to data citing poor surgical outcomes, advances in transcatheter techniques and imaging modalities have reframed the approach to tricuspid valve disease in promising new ways.MethodsHere we sought to provide a landscape review of the current state of the field for transcatheter tricuspid valve interventions. We first start with a descriptive overview of the tricuspid valve, reviewing the anatomy, imaging characteristics, and the current guidelines for tricuspid interventions. We then review both transcatheter valve repair and valve replacement modalities, highlighting the devices, techniques, and valves currently under investigation, summarizing available outcomes data for each modality when possible.Results and ConclusionOur aim in writing this landscape review is the create an all-encompassing, up-to-date resource for clinicians to refer to when seeking to learn about the current state of transcatheter tricuspid valve interventions. We also hope to highlight the exciting promise of transcatheter tricuspid valve replacement in appropriate patients, and review the valves currently under development for use in the tricuspid position.

Transcatheter Interventions for Tricuspid Valve Disease: What to Do and Who to Do It On

Tricuspid valve disease, and particularly the management of severe tricuspid regurgitation (TR), has gained momentum in recent years. Although it is well known that this frequent condition is associated with poor clinical outcomes, these patients have been classically managed medically, leading to end-stage right ventricular heart failure. Moreover, late referral to surgery has contributed to a high rate of periprocedural complications and in-hospital surgical mortality. Thus, the development of a less invasive catheter-based therapy would be of high clinical relevance in this context. Several transcatheter tricuspid valve intervention (TTVI) devices have been developed in recent years. The particular characteristics of the tricuspid valve (large noncalcific annulus, presence of chief surrounding structures such as the conduction system or the right coronary artery) make multimodality imaging (eg, transesophageal echocardiography, computed tomography) key in the preprocedural assessment of TTVI. According to their mechanism of action and therapeutic target, TTVI includes transcatheter repair either with coaptation or annuloplasty systems, caval valve devices, and transcatheter tricuspid valve replacement. The initial TTVI experience showed that most procedures were well tolerated, with high procedural success and low in-hospital and early mortality. Also, most TTVI recipients improved their functional status and recent data suggest improved outcomes compared with medical management. However, the rate of significant residual TR after transcatheter tricuspid valve repair remains high and very scarce data exist on longer term (beyond 6-12 months) outcomes. The present review provides an overview regarding the framework of chronic TR and TTVI therapeutic options, and describes the updated current evidence in this challenging field.

Thoracoscopic assistance in tricuspid valvuloplasty in an unarrested state: a case report and literature review

Tricuspid regurgitation, a common tricuspid lesion, consists of organic and functional tricuspid insufficiency (FTI). FTI is usually secondary to the valvular heart disease in left atrium. Pulmonary hypertension may result in right ventricular and tricuspid annular enlargement. This report documents our findings of tricuspid valve surgery under cardiac arrest with telescopic assistance. A 65-year-old female patient referred to our department received thoracoscope-associated tricuspid valvuloplasty. The patient exhibited a history of intermittent dyspnea and shortness of breath for 20 years, together with edema in the lower limbs for 3 months. A small incision was made, prior to an additional incision of about 3 cm in length before localization was performed at the lateral side of the 4th midclavicular line. The satellite hole was localized at the 5th midaxillary line. The operation was completed under cardiopulmonary bypass with a beating heart. Echocardiogram (ECG) analysis 10 days post-surgery indicated no clinically significant findings. Finally, the patient was discharged with slight tricuspid regurgitation .Thoracoscopy-associated heart surgery reduces postoperative pain and shortens postoperative recovery time. It is in line with the concept of rapid recovery and beauty needs. Our data confirmed that thoracoscope-assisted tricuspid valvuloplasty in an unarrested state was effective for the treatment of patients with tricuspid insufficiency, secondary to post-cardiac surgery.

Functional tricuspid regurgitation: indications, techniques, and outcomes

Functional tricuspid regurgitation (TR) results from asymmetric dilation of the tricuspid valve annulus. This often occurs due to right ventricular enlargement and dysfunction as a consequence of myocardial or valvular abnormalities of the left heart. Even mild TR at the time of left-sided valvular surgery may worsen postoperatively, which carries poor prognostic implications. In spite of data revealing poor outcomes associated with residual TR, surgery for functional TR remains underutilized. Surgical repair techniques for TR include placement of a rigid or semi-rigid tricuspid annular ring, which has been shown to provide superior longevity compared with suture and flexible band repair techniques. Additionally, emerging percutaneous annuloplasty techniques to correct functional TR can expand interventional treatment options to patients who would otherwise carry prohibitive operative risk.

Evaluation and Management of Primary Tricuspid Regurgitation

Tricuspid regurgitation (TR) is a highly prevalent echocardiographic finding in general population being present in almost 80% to 90% of them. However, TR is mild or functional rather than organic in majority of people. Significant TR was seen in 14.8% of adult men and 18.4% of adult women, respectively. Of all the significant TRs, approximately 8% to 10% are primary. Mild TR is benign but moderate-to-severe TR tends to progress and carries significant morbidity and mortality. Tricuspid valve disease is either primary or secondary (functional) in nature. Valve leaflets are predominantly diseased in primary TR, whereas annular dilatation is the main culprit in secondary TR. Of all the heart valves, tricuspid valve was the most neglected valve till a decade ago, though there was enough evidence to show that moderate to severe TR was not as benign as was assumed. With the availability of 2-dimensional echocardiography (2D echo) and transesophageal echocardiography, we are able to diagnose and determine the severity as well as etiology of TR. Although surgical therapy remains the gold standard for severe primary tricuspid valve disease, it continues to suffer from one of the highest morbidity and mortality rates among all cardiac valve-related surgeries even in the hands of experienced surgeons. For the same reason, majority of patients are not referred or subjected to surgical therapy. Therefore, there is an unmet need for less invasive and safer form of therapy to overcome this hurdle. So, several less-invasive and innovative technologies for treating patients with severe tricuspid valve disease at high surgical risk are being developed. Some of them have already been used for treatment of severe mitral regurgitation. They are being adopted for the treatment of severe TR. This review provides a comprehensive picture of newer guidelines and latest technologies and their impact on diagnosis and outcome of high-risk TV disease.

Catheter-based treatment of tricuspid regurgitation: state of the art

Tricuspid regurgitation is a highly prevalent condition, with detrimental effects on long-term survival. However, it has been historically neglected, and only surgically addressed when symptomatic diuretic agents proved insufficient to alleviate congestion. Besides, mortality rates of isolated tricuspid regurgitation surgery have been persistently high, even in contemporary series. This has led to the advent of a myriad of transcatheter tricuspid valve interventions mimicking current surgical technologies, for which a comprehensive imaging work-up holds the key for proper patient selection and intraprocedural monitoring. Although initially designed for compassionate use patients, growing experience and encouraging results of these less-invasive technologies are broadening the spectrum of beneficiaries. In this review, we will focus on the current picture of transcatheter tricuspid valve interventions, with special interest on the current understanding of pathoanatomic tricuspid regurgitation progression, preprocedural multimodality imaging and the latest experience on the different transcatheter devices.

Transcatheter therapies for severe tricuspid regurgitation. Quo vadis?

Moderate-to-severe tricuspid regurgitation (TR) is common and is associated with a poor prognosis. To date, most patients are undertreated; therefore, transcatheter options could be clinically impactful in those who are denied surgery. Several transcatheter solutions have been developed that address the problem via leaflet enhancement, annuloplasty, or heterotopic implantation of self-expandable or balloon-expandable valves in the caval veins. A comprehensive patient evaluation, based on multimodality imaging techniques for a better understanding of the valvular pathology and TR mechanism, remains paramount for an appropriate device selection. To date, several trials have shown the feasibility and safety of a multitude of devices in this setting, but data from randomized clinical trials regarding clinical benefit based on hard endpoints are still lacking. Although the optimal patient profile and timing of intervention remain under investigation, data from available studies indicate that an earlier treatment referral, before onset of irreversible right ventricular remodeling, could be beneficial. This review discusses the present landscape and future implications of transcatheter therapies for severe TR.

New Insights into Valve Hemodynamics

Heart valve diseases are common disorders with five million annual diagnoses being made in the United States alone. All heart valve disorders alter cardiac hemodynamic performance; therefore, treatments aim to restore normal flow. This paper reviews the state-of-the-art clinical and engineering advancements in heart valve treatments with a focus on hemodynamics. We review engineering studies and clinical literature on the experience with devices for aortic valve treatment, as well as the latest advancements in mitral valve treatments and the pulmonic and tricuspid valves on the right side of the heart. Upcoming innovations will potentially revolutionize treatment of heart valve disorders. These advancements, and more gradual enhancements in the procedural techniques and imaging modalities, could improve the quality of life of patients suffering from valvular disease who currently cannot be treated.

Current state of transcatheter tricuspid valve repair

Tricuspid regurgitation (TR) is a common valvular heart disease affecting >1.6 million people in the United States (US) and >70 million people worldwide. The age- and sex-adjusted prevalence of more than or equal to moderate TR in the US is estimated to be 0.55%. One-year mortality increases with increasing severity of TR. Yet, the majority of patients with severe TR are managed medically in the absence of another indication for cardiac surgery, and isolated tricuspid valve (TV) surgery remains infrequent. To address this unmet clinical need, various transcatheter TV therapies are now being developed as an alternative to surgery in extreme- and high-risk patients with severe functional TR. Transcatheter TV repair devices are aimed at improving leaflet coaptation either directly by bringing the leaflets together (leaflet/coaptation devices) or indirectly by repairing the dilated annulus (annuloplasty devices). In this review, we describe the current state of transcatheter TV repair therapies and summarize the available data on the efficacy and safety of various devices. Procedural and clinical outcomes of transcatheter TV repair therapies are expected to improve in the coming years with technological advancement, newer device iterations, and increased experience in this field. Appropriate patient selection, optimal timing of intervention, and evaluation of long-term outcomes and device durability will be key in ongoing and future studies.

Developments in transcatheter tricuspid valve therapies

Introduction: Transcatheter tricuspid valve (TV) procedures emerged as an alternative to surgery for symptomatic high-risk patients with severe tricuspid regurgitation.Areas covered: A literature search was performed using PubMed. Authors review clinical evidence in this field, the imaging features and the developments in TV transcatheter technologies. Currently, transcatheter devices for TV procedures can be allocated into four main groups: 1) those ones targeting leaflet malcoaptation, 2) those addressing annular dilatation, 3) those performing heterotopic valve implantation and 4) those onesaccomplishing a complete transcatheter replacement of the valve.Expert opinion: Actually, encouraging results are provided by initial experience in the field of transcatheter TV procedures. However, this field remains full of challenges that faced could lead to better results and prognosis for the patients. The next steps in this emerging field will need to focus on accurate patient selection, an early patient referral and on studies comparable and providing long-term data.

Imaging Needs in Novel Transcatheter Tricuspid Valve Interventions

The advent of novel transcatheter therapies for severe tricuspid regurgitation (TR) has attracted much attention. Novel 3-dimensional imaging techniques have permitted analysis of the tricuspid valve (TV) anatomy from unparalleled views and better understanding of the underlying pathophysiology of TR. Grading TR and assessment of right ventricular function remain challenging, and although 2-dimensional echocardiography is the mainstay imaging technique to evaluate patients with severe TR the use of 3-dimensional echocardiography and cardiovascular magnetic resonance is increasing. The number of transcatheter interventions for TR is growing, and procedural success relies significantly on the pre-procedural evaluation of the anatomy of the TV, etiology and severity of TR, right ventricular size and function, and importantly, the anatomic relationships of the TV. The role of multimodality imaging in patient selection and procedural planning for transcatheter TV repair is reviewed.

[Transcatheter treatment of tricuspid regurgitation]

Tricuspid regurgitation is serious disease for which surgical correction is underperformed because of a prohibitive risk. It is responsible for a 50% mortality at 3 years which is decreased by surgical treatment. However, only a negligible proportion of patients undergoes surgery. In this context, there is currently an unmet need for percutaneous treatment technique. Several technologies are undergoing preclinical or early clinical development. These techniques aim to mimic the different surgical strategies used for the treatment of tricuspid regurgitation. Thus, some target the leaflets, the tricuspid annulus or offer a complete tricuspid valve replacement. Before planning a transcatheter tricuspid intervention, a comprehensive evaluation is mandatory, addressing the patient clinical status and comorbidities, the tricuspid regurgitation ad its consequences on right heart and, the anatomy of the tricuspid annulus and the right heart to determine if the patient is eligible for the chosen technique. This article will review the indications, contraindications and exams to perform before transcatheter tricuspid intervention and will then detail the different strategies available or undergoing development.

The Forgotten, Not Studied or Not Valorized Tricuspid Valve: The Transcatheter Revolution Is Coming

The tricuspid valve (TV) has been known as the forgotten valve. However, considering recent information from scientific studies, this nomenclature may need to be adjusted for the valve, which also needs to be better studied and understood. For decades, tricuspid regurgitation (TR) was not fully appreciated and was never the priority. However, studies have revealed that such pathology is related to a possible negative impact on prognosis of patients. Severe TR is a predictor of higher mortality. For the treatment of TR, repair or valve replacement can be performed. Repair techniques can be performed on the annulus (suture annuloplasty or ring implant), on the leaflets (e.g. triangular resection), on the cords (transfers or new cords) and on the papillary muscles (e.g. sliding technique). The anatomical characteristics of the TV determine the repair technique to be used. In some cases, valve repair is not possible and/or not indicated and valve replacement is selected based on the strategy. Nowadays transcatheter therapies have been used and studied. The main transcatheter strategies for the treatment of TR are based on reduction of the annulus (Cardioband, Trialign, TriCinch, Millipede and TRAIPTA), improvement of the leaflet coaptation (Mitraclip, FORMA device, PASCAL system, and TV occluder), reduction of the reflux for the vena cava system (Tric valve and Sapien valve implant), and valve implants (Navigate, Trisol, Sapien, Melody). In this context, there are still other devices (such as Tricentro, Pasta, etc.) being developed and tested throughout several phases of research. In the future, improved knowledge of the TV and the evolution of transcatheter treatments will alter the history of the TV. The transcatheter revolution is coming!

Specific Anatomic Considerations for Tricuspid Interventions

PURPOSE OF REVIEW

This review discusses the normal anatomy and pathology of the tricuspid valve (TV) and right side of the heart. Emphasis is on those anatomic and pathologic features relevant to interventions intended to restore normal function to the TV in disease states.

RECENT FINDINGS

TV pathology is less common than aortic and mitral valve pathology, and treatment and outcomes for interventions face considerable hurdles. New innovations and early data showing safety and efficacy in transcatheter interventions have transformed TV interventions into the next frontier in cardiac valve disease treatment. Certain features of the TV and right heart have presented themselves as potential targets, as well as impediments, for TV intervention. The causes of TV pathology and the anatomy of the TV and right heart bring unique challenges to intervention. Approaches to intervention will continue to progress and change the way we view and treat TV pathology.

Update on the Current Landscape of Transcatheter Options for Tricuspid Regurgitation Treatment

Most patients with severe tricuspid regurgitation lack treatment options because of prohibitive surgical risk. New transcatheter treatments under development and investigation might be able to address this unmet clinical need. This article gives an update on the landscape of devices for transcatheter tricuspid regurgitation treatment including different approaches (i.e. repair with leaflet approximation or annuloplasty and replacement using orthotopic or heterotopic valves) at different stages of development, from experimental to clinical trial. Repair devices such as the Cardioband or the MitraClip are leading the field with promising preliminary data and further trials are ongoing. However, with implantations of the Gate bioprosthesis, replacement devices are catching up. Potential advantages of different approaches and most recent data are discussed.

Transcatheter Tricuspid Valve Interventions: An Emerging Field

PURPOSE OF REVIEW

This review aims to provide an updated overview and a clinical perspective on novel transcatheter tricuspid valve interventions (TTVI), highlighting potential challenges and future directions.

RECENT FINDINGS

Severe tricuspid regurgitation (TR) is a predictor of mortality. However, a sizeable number of patients remain untreated until the end-stage when cardiac surgery presents a prohibitive risk. The emergent need in finding a treatment for patients with TR, deemed for surgery options, has encouraged the development of TTVI. These procedures mimic classical surgery techniques and are mainly divided in four categories: annuloplasty and coaptation devices, edge-to-edge techniques and transcatheter tricuspid valve replacement. Early studies showed promising results, but long-term follow-up data are not available. For patients with severe TR and high surgical risk, several percutaneous options are available. However, these therapies are in a growing phase and bigger studies and long term follow-up are needed to prove their efficacy.

Transcatheter pledget-assisted suture tricuspid annuloplasty (PASTA) to create a double-orifice valve

OBJECTIVES

Pledget-assisted suture tricuspid valve annuloplasty (PASTA) is a novel technique using marketed equipment to deliver percutaneous trans-annular sutures to create a double-orifice tricuspid valve.

BACKGROUND

Tricuspid regurgitation is a malignant disease with high surgical mortality and no commercially available transcatheter solution in the US.

METHODS

Two iterations of PASTA were tested using trans-apical or trans-jugular access in swine. Catheters directed paired coronary guidewires to septal and lateral targets on the tricuspid annulus under fluoroscopic and echocardiographic guidance. Guidewires were electrified to traverse the annular targets and exchanged for pledgeted sutures. The sutures were drawn together and knotted, apposing septal and lateral targets, creating a double orifice tricuspid valve.

RESULTS

Twenty-two pigs underwent PASTA. Annular and chamber dimensions were reduced (annular area, 10.1 ± 0.8 cm2 to 3.8 ± 1.5 cm2 (naïve) and 13.1 ± 1.5 cm2 to 6.2 ± 1.0 cm2 (diseased); septal-lateral diameter, 3.9 ± 0.3 mm to 1.4 ± 0.6 mm (naïve) and 4.4 ± 0.4 mm to 1.7 ± 1.0 mm (diseased); and right ventricular end-diastolic volume, 94 ± 13 ml to 85 ± 14 ml (naïve) and 157 ± 25 ml to 143 ± 20 ml (diseased)). MRI derived tricuspid regurgitation fraction fell from 32 ± 12% to 4 ± 5%. Results were sustained at 30 days. Pledget pull-through force was five-fold higher (40.6 ± 11.7N vs 8.0 ± 2.6N, P < .01) using this strategy compared to single puncture techniques used to anchor current investigational devices. Serious complications were related to apical access.

CONCLUSIONS

PASTA reduces annular dimensions and tricuspid regurgitation in pigs. It may be cautiously applied to selected patients with severe tricuspid regurgitation and no options. This is the first transcatheter procedure, to our knowledge, to deliver standard pledgeted sutures to repair cardiac pathology.

Multi-Modality Imaging in the Evaluation and Treatment of Tricuspid Regurgitation

PURPOSE OF REVIEW

The goal of this review is to cover the epidemiology of tricuspid regurgitation (TR), anatomy of the tricuspid valve (TV), and the mechanisms and modern treatment of TR. The focus will be on the role of echocardiography, cardiac CT, and MRI to determine the mechanism, severity, and management strategies of TR.

RECENT FINDINGS

The evaluation and management of TR is a rapidly growing field with significant advances in both imaging and interventions. Important advances have been made to understand TV anatomy and physiology in 3D echo, CT, and MRI. Additional understanding of the abnormal outcomes in both primary TR and secondary TR have been appreciated. Multiple transcatheter devices have reached the stage of early trials in high surgical risk cohorts with favorable initial findings. TR is a significant cardiovascular problem and vastly undertreated in the present era. There has been tremendous growth in knowledge of mechanisms of TR, its prognostic implications, timing of intervention, and development of novel treatment strategies. Multimodality imaging plays a key role in evaluation and treatment of this condition.

Percutaneous tricuspid valve therapies: the new frontier

Moderate-to-severe tricuspid regurgitation (TR) affects ∼1.6 million patients in the USA, of whom only 8000 undergo tricuspid surgery annually; this results in an extremely large number of untreated patients with significant TR. Therefore, there is a large unmet clinical need for patients with severe TR who are not referred for conventional surgery, mainly due to expected high surgical risk. Percutaneous procedures are an attractive alternative to surgery for patients deemed to be high-risk surgical candidates. Whereas over the past few years, the development and clinical use of percutaneous approaches to the aortic valve and mitral valve have been widespread, few data are available about the feasibility and the efficacy of the percutaneous tricuspid valve treatment. This review will explore the available technologies, which are today under evaluation and the preliminary clinical results.

Current Treatment Strategies for Tricuspid Regurgitation

PURPOSE OF REVIEW

Tricuspid regurgitation is common; however, recognition and diagnosis, clinical outcomes, and management strategies are poorly defined. Here, we will describe the etiology and natural history of tricuspid regurgitation (TR), evaluate existing surgical outcomes data, and review the evolving field of percutaneous interventions to treat TR.

RECENT FINDINGS

Previously, the only definitive corrective therapy for TR was surgical valve repair or replacement which is associated with significant operative mortality. Advances in percutaneous valve repair techniques are now being translated to the tricuspid valve. These novel interventions may offer a lower-risk alternative treatment in patients at increased surgical risk. Significant TR adversely impacts survival. Surgery remains the only proven therapy for treatment of TR and may be underutilized due to mixed outcomes data. Early experience with percutaneous interventions is promising, but large clinical experience is lacking. Further study will be required before these therapies are introduced into broader clinical practice.

Mechanism and Implications of the Tricuspid Regurgitation

The tricuspid valve was virtually ignored for a long time in the past. However, significant tricuspid regurgitation (TR) often accompanies left-side heart valve pathology and does not always reverse with its correction. If left untreated, TR can progress and result in progressive right ventricular failure. Current guideline recommendations still hold minor differences. Nevertheless, there is a consensus to operate on patients with severe TR undergoing left-sided valve surgery (class I) or those with mild to moderate TR with a dilated annulus (≥40 or ≥21 mm 2 , Class IIa). However, in case of the primary TR, surgical options is limited by a relatively high risk of mortality and morbidity. For these patients, new percutaneous approaches are becoming available but no long-term data are still available. In this review, we provide a comprehensive overview of the epidemiological and pathophysiological aspects of TR, and the current and future directions of therapy.

Percutaneous Treatment of the Tricuspid Valve Disease: New Hope for the "Forgotten" Valve

Tricuspid valve disease is a frequent condition but is currently undertreated. A limited number of patients undergo an isolated surgical tricuspid repair, and this intervention is associated with poor outcomes, especially in patients with previous cardiac surgery. Most patients are only medically treated, despite the impact of severe tricuspid regurgitation on functional status and long-term survival. Transcatheter therapies represent a promising alternative for patients with severe tricuspid regurgitation and high surgical risk. In the last few years, several percutaneous alternatives have been developed for the treatment of functional tricuspid regurgitation. Imaging techniques play an indispensable role in patient selection, procedural guidance and follow-up. The current available transcatheter options for native tricuspid valve disease can be divided into 3 main groups: heterotopic caval valve implantation, annuloplasty devices, and coaptation devices. In patients with previous tricuspid valve surgery, transcatheter valve-in-valve and valve-in-ring procedures have been reported. This review provides a detailed analysis of the novel transcatheter alternatives for the treatment of tricuspid valve disease that have already been successfully implanted in humans, as well as the most important aspects of tricuspid valve anatomy and imaging assessment.

Effects of Cinching Force on the Tricuspid Annulus: A Species Comparison

PURPOSE

Tricuspid annuloplasty rings are commonly used to cinch an enlarged tricuspid annulus back to its original shape and size in patients with severe functional tricuspid regurgitation. However, the invasive operation is contraindicated for patients at risk for reoperation. Fortunately, transcatheter repair procedures, currently in the development process, are minimally invasive alternatives to current repair techniques. This study aims to determine the species-dependence of cinching force with the potential of informing transcatheter repair design by quantifying the minimum required cinching force necessary to reduce tricuspid regurgitation.

METHODS

The cinching force necessary to reduce the septal-lateral diameter of a dilated annuls was quantified and compared in ten ovine hearts and nine porcine hearts. Additionally, a deparaffinization protocol and Verhoeff-Van Gieson stain were used to compare the microscopic structure of tissue samples at different stages of the experimental procedure in the two species.

RESULTS

The maximum annulus dilation observed for the porcine was 11.2%, and the maximum cinching force was 0.40 ± 0.12 N. As previously demonstrated, ovine hearts yielded a maximum annulus dilation and cinching force of 8.82% and 0.38 ± 0.09 N respectively. Histological stains revealed no gross tissue differences between ovine and porcine septal or free wall tissues.

CONCLUSION

The cinching force was not species dependent between ovine and porcine models. This study is an essential first step for determining which animal model should be utilized for the development of transcatheter devices.

Advances in percutaneous interventional therapies: the tricuspid valve

Tricuspid regurgitation (TR) is a prevalent valve condition, with an estimated 1.6 million people in the USA living with moderate or greater severity. Functional TR, which predominantly develops due to left-sided heart disease, is the predominant condition affecting the tricuspid valve in the Western world and severe TR is associated with substantial morbidity and mortality. In part, due to a prolonged latency period with insidious symptoms, patients are often referred for surgery at advanced stages, with associated increased or prohibitive surgical risk. In addition, surgical treatment can result in high rates of recurrence. Therefore, there is an unmet need for percutaneous therapies that may provide a relatively low-risk treatment option. There are several devices with early human feasibility data available that will be reviewed in this article.

Current transcatheter devices to treat functional tricuspid regurgitation with discussion of issues relevant to clinical trial design

Functional or secondary tricuspid regurgitation (TR) has seen increased attention in recent times as relationships with clinically-relevant outcomes have come to light. Despite the association of increased mortality with significant TR, the disease remains under-recognized and thus relatively untreated. In addition, the disease itself has not been extensively studied and the interactions between annular dilatation, right heart disease and pulmonary hypertension are poorly understood. However, the high mortality and recurrence rate with current surgical replacement or repair techniques is well recognised, opening the door to transcatheter therapies for functional TR. The current perspective reviews the rationale for transcatheter solutions, describes some of the current approaches and discusses the ongoing questions of a poorly-studied condition which may limit the design of clinical trials for this disease.

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.