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

Beyond Medical Therapy-An Update on Heart Failure Devices

Heart failure (HF) is a complex and progressive disease marked by substantial morbidity and mortality rates, frequent episodes of decompensation, and a reduced quality of life (QoL), with severe financial burden on healthcare systems. In recent years, several large-scale randomized clinical trials (RCTs) have widely expanded the therapeutic armamentarium, underlining additional benefits and the feasibility of rapid titration regimens. This notwithstanding, mortality is not declining, and hospitalizations are constantly increasing. It is widely acknowledged that even with guideline-directed medical therapy (GDMT) on board, HF patients have a prohibitive residual risk, which highlights the need for innovative treatment options. In this scenario, groundbreaking devices targeting valvular, structural, and autonomic abnormalities have become crucial tools in HF management. This has led to a full-fledged translational boost with several novel devices in development. Thus, the aim of this review is to provide an update on both approved and investigated devices.

Percutaneous repair of tricuspid regurgitation

Tricuspid regurgitation (TR) is common both in patients with left side valvular heart disease and in patients with permanent atrial fibrillation and is associated with increased mortality, morbidity, and an increased risk of hospitalization. Surgery for isolated tricuspid repair is a viable option but burdened by a high-operative risk and a post-operative course characterized by high morbidity. Recently, percutaneous interventional techniques have emerged as a viable option in selected high-risk patients who may clinically benefit from tricuspid valve repair. The purpose of this article is to provide an overview of the current state of transcatheter restorative treatment of TR by providing an overview of new devices in clinical development.

Heart Transplantation in a Patient With a Heterotopic Percutaneous Tricuspid Valve Prosthesis: A Case Report

The bicaval transcatheter prosthesis (TricValve) allows the treatment of cava reflux in patients with severe tricuspid regurgitation and high surgical risk. It consists of the implantation of 2 self-expanding valves in both vena cava without directly approaching the native tricuspid valve. Heart transplantation in this setting may require some modifications compared with the conventional bicaval technique. We describe the clinical case of a 69-year-old woman with a background of rheumatic mitral valve disease who required a mitral valve replacement a few decades before. Ongoing clinical deterioration with biventricular dysfunction and severe tricuspid regurgitation was treated with a percutaneous bicaval heterotopic self-expanding valve system, with no clinical benefit. The patient underwent an elective heart transplantation. For the surgical approach, venous cannulation was performed percutaneously for both the right internal jugular and right femoral vein. Due to the impossibility of extracting percutaneous caval valves, the biatrial technique was selected for heart implantation. The postoperative course was difficult, but the patient was successfully discharged home 2 months postoperatively. She remains in good clinical condition with normal heart function 1 year after the transplant. To our knowledge, this is the first report describing a heart transplant in a patient with a bicaval transcatheter prosthesis.

The Development of a Permanent Implantable Spacer with the Function of Size Adjustability for Customized Treatment of Regurgitant Heart Valve Disease

The Pivot Mandu is an innovative device featuring a leak-tight adjustable 3D balloon spacer, incorporating inner mesh support, an outer e-PTFE layer, and a compliant balloon in the middle layer with a specialized detachable system. To assess its feasibility, proof of concept was rigorously evaluated through bench testing and survival porcine animal experiments. The results demonstrated successful remote inflation of the balloon system, with the balloon spacer exhibiting sustained patent and functional integrity over an extended observation period of up to 6 months. A noteworthy feature of the newly designed 3D balloon spacer is its capability for easy size adjustment during procedures, enhancing its adaptability and practicality in clinical settings. This three-layered 3D balloon spacer, with its established long-term patency, exhibits highly encouraging outcomes that hold promise in overcoming the current limitations of spacer devices for heart valve diseases. Given the compelling results from preclinical investigations, the translation of the Pivot Mandu into human trials is strongly warranted.

Echocardiographic Imaging in Transcatheter Structural Intervention: An AAE Review Paper

Transcatheter structural heart intervention (TSHI) has gained popularity over the past decade as a means of cardiac intervention in patients with prohibitive surgical risks. Following the exponential rise in cases and devices developed over the period, there has been increased focus on developing the role of "structural imagers" amongst cardiologists. This review, as part of a growing initiative to develop the field of interventional echocardiography, aims to highlight the role of echocardiography in myriad TSHIs available within Asia. We first discuss the various echocardiography-based imaging modalities, including 3-dimensional echocardiography, fusion imaging, and intracardiac echocardiography. We then highlight a selected list of structural interventions available in the region-a combination of established interventions alongside novel approaches-describing key anatomic and pathologic characteristics related to the relevant structural heart diseases, before delving into various aspects of echocardiography imaging for each TSHI.

Biomechanical performance of the Bicaval Transcatheter System for the treatment of severe tricuspid regurgitation

Introduction: Tricuspid regurgitation (TR) is a relatively common valvular disease, which can result from structural abnormalities of any anatomic part of the tricuspid valve. Severe TR is linked to congestive heart failure and hemodynamic impairment, resulting in high mortality when repaired by elective surgery. This study was undertaken to quantify the structural and hemodynamic performance of the novel Transcatheter Bicaval Valves System (TricValve) percutaneously implanted in the superior vena cava (SVC) and inferior vena cava (IVC) of two patients with severe TR and venous congestion. Methods: After developing the SVC and IVC device models, the contact pressure exerted on the vena cava wall was obtained by computational analysis. Both smoothed-particle hydrodynamics (SPH) and computational fluid dynamics were carried out to quantify caval reflux in the right atrium and the pressure field of pre- and post-TricValve scenarios, respectively. Results: Analysis of contact pressure highlighted the main anchoring area of the SVC device occurring near the SVC device belly, while the IVC device exerted pronounced forces in the device's proximal and distal parts. SPH-related flow velocities revealed the absence of caval reflux, and a decrease in time-averaged pressure was observed near the SVC and IVC after TricValve implantation. Discussion: Findings demonstrated the potential of computational tools for enhancing our understanding of the biomechanical performance of structural tricuspid valve interventions and improving the way we design next-generation transcatheter therapies to treat the tricuspid valve with heterotopic caval valve implantation.

A Novel Device for Tricuspid Regurgitation Reduction Featuring 3-Dimensional Leaflet and Atraumatic Anchor: Pivot-TR System

A new device called the Pivot-TR system was designed to treat tricuspid regurgitation with a novel spacer crossing the valve vertically. Its unique atraumatic anchoring system composed of both the elephant long nose and the inferior vena cava spiral anchor, in addition to the relatively easy implantation mechanism, enabled easy retrieval of the system later on. The system showed promising feasibility and safety results in this swine-based animal experiment, which should encourage human translation study.

Novel treatment of atrial functional tricuspid regurgitation using transcatheter bicaval valve implantation (TricValve)

BACKGROUND

Transcatheter tricuspid valve intervention has recently emerged as a viable alternative to surgery for patients with symptomatic severe tricuspid regurgitation (TR). Though usually performed on the basis of compassionate grounds, we are now exploring the extension of its usage as an elective option in a patient with severe atrial functional tricuspid regurgitation.

AIMS

The aim of this study was to select a suitable patient and proceed with the implantation of the TricValve in order to provide symptomatic relief as well as to improve morbidity and mortality.

METHODS

A 67-year-old woman had underlying atrial fibrillation and severe tricuspid regurgitation. Despite optimised medical therapy, she remained symptomatic with elevated NT-proBNP levels. As the patient refused surgery on multiple occasions, we chose a percutaneous procedure guided by transoesophageal echocardiography and fluoroscopy.

RESULTS

The procedure was uneventful and the patient was discharged. At 3-month follow-up, there was marked improvement clinically and biochemically.

CONCLUSIONS

Bicaval valve implantation with the TricValve is a viable alternative to surgery in patients with symptomatic severe tricuspid regurgitation. This intervention is crucial as we are now able to intervene before irreversible right ventricular dysfunction sets in.

Edge-to-Edge Repair for Tricuspid Valve Regurgitation. Preliminary Echo-Data and Clinical Implications from the Tricuspid Regurgitation IMAging (TRIMA) Study

Background: The natural history of tricuspid valve regurgitation (TR) is characterized by poor prognosis and high in-hospital mortality when treated with isolated surgery. We report the preliminary echocardiographic and procedural results of a prospective cohort of symptomatic patients with high to prohibitive surgical risk and at least severe TR who underwent transcatheter edge-to-edge repair through the TriClipTM system. Methods: From June 2020 to March 2022, 27 consecutive patients were screened, and 13 underwent transcatheter TriClipTM repair. In-hospital, 30-day and six-month clinical and echocardiographic outcomes were collected. Results: Nine patients had severe, three massive and one baseline torrential TR. Sustained TR reduction of ≥1 grade was achieved in all patients, of which 90% reached a moderate TR or less. On transthoracic echocardiographic examination, there were significant reductions in vena contracta width (p < 0.001), effective regurgitant orifice area (p < 0.001) and regurgitant volume (p < 0.001) between baseline and hospital discharge. We also observed a significant reduction in tricuspid annulus diameter (p < 0.001), right ventricular basal diameter (p = 0.001) and right atrial area (p = 0.026). Conclusion: Treatment with the edge-to-edge TriClip device is safe and effective. The resulting echocardiographic improvements indicate tricuspid valve leaflet approximation does not just significantly reduce the grade of TR but also affects adjacent structures and improves right ventricular afterload adaptation.

Focus on Diagnosis and Prognosis to Guide Timing of Intervention in Valvular Heart Disease

Purpose of Review

The present article reviews the role of multimodality imaging to improve risk stratification and timing of intervention in patients with valvular heart disease (VHD), and summarizes the latest developments in transcatheter valve interventions.

Recent Findings

Growing evidence suggests that intervention at an earlier stage may improve outcomes of patients with significant VHD. Multimodality imaging, including strain imaging and tissue characterization with cardiac magnetic resonance imaging, has the ability to identify early markers of myocardial damage and can help to optimize the timing of intervention. Transcatheter interventions play an increasing role in the treatment of patients who remain at high surgical risk or present at a late stage of their disease.

Summary

Multimodality imaging identifies markers of cardiac damage at an early stage in the development of VHD. Together with technological innovations in the field of percutaneous valvular devices, these developments have the potential to improve current management and outcomes of patients with significant VHD.

Computationally Assessed 3D Anatomical Proximities and Spatial Relationships Among the Tricuspid Valve Annulus, Right Coronary Artery, and Triangle of Koch: Implications for Transcatheter Tricuspid Annuloplasty Repair

Background

Transcatheter-based annuloplasty therapies for tricuspid regurgitation have demonstrated significant development over recent years. However, the tricuspid valve and neighboring vasculature and conductive tissue regions can present anatomical and device deployment challenges. This present study investigated the anatomical dimensions and spatial relationships of the cardiac structures essential to percutaneous annuloplasty procedures: the tricuspid annulus (TA), right coronary artery (RCA), and triangle of Koch border region.

Methods

Measurements were derived from computational three-dimensional reconstructions of static magnetic resonance imaging scans of perfusion-fixed human hearts (n = 82) with preserved right-sided heart anatomies. This specimen set included heart samples presenting with prediagnosed atrioventricular valvular regurgitation.

Results

Our anatomical assessments demonstrated that the TA to RCA proximities were intensified with the presence of atrioventricular valvular regurgitation, compared with healthy heart specimens. The minimal distances were frequently located between the lateral and posterior annular points. This annular region corresponds to the RCA distal segments and posterior descending branch origins. Greater portions and incidences of the RCA coursing parallel or inferior to the TA plane were recorded for these diseased hearts. Patient demographic variables (gender, age, and body mass index) were insignificant determinants of change for a majority of our results.

Conclusions

These three-dimensional reconstructions provide insights to guide the development and future iterations of transcatheter tricuspid valve annuloplasty systems with regards to device anchoring, annular geometry, tissue proximities, and implantation considerations.

Six-Month Outcomes of the TricValve® System in Patients with Tricuspid Regurgitation: TRICUS EURO Study

BACKGROUND

Severe tricuspid regurgitation (TR) is frequently associated with significant morbidity and mortality; such patients often deemed to be at high surgical risk. Heterotopic bi-caval stenting is an emerging, attractive transcatheter solution for these patients.

OBJECTIVES

To evaluate the 30-day safety and 6-month efficacy outcomes of specifically designed bioprosthetic valves for the superior and inferior vena cava.

METHODS

TRICUS EURO is a non-blinded, non-randomized, single-arm, multicenter, prospective trial that enrolled patients from 12 European centers between December 2019 to February 2021. High risk individuals with severe symptomatic TR despite optimal medical therapy were included. Primary end point was quality of life (QOL) improvement measured by Kansas City Cardiomyopathy Questionnaire (KCCQ12) and New York Heart Association functional class (NYHA) improvement at 6-month follow-up.

RESULTS

35 patients (mean age 76±6.8 years; 83% women) were treated with TricValve® system. All patients at baseline were at NYHA ≥ 3 status. At 30-days, procedural success was 94% with no procedural deaths or conversions to surgery. A significant increase in QOL at 6-months follow-up was observed (baseline and 6-month KCCQ: 42.01±22.3 vs. 59.7±23.6 respectively; p=0.004), correlating with a significant improvement in NYHA functional class with 79.4% of patients noted to be in class I or II at 6 months (p=0.0006). The 6-month all-cause mortality and heart failure hospitalization rates were 8.5% and 20%, respectively.

CONCLUSIONS

The dedicated bi-caval system for treating severe, symptomatic TR was associated with high procedural success rate and significant increase in both, QOL and functional improvements at 6-months follow-up.

Transcatheter edge-to-edge repair of tricuspid regurgitation in the Netherlands: state of the art and future perspectives

Despite the high prevalence and adverse clinical outcomes of severe tricuspid regurgitation (TR), conventional treatment options, surgical or pharmacological, are limited. Surgery is associated with a high peri-operative risk and medical treatment has not clearly resulted in clinical improvements. Therefore, there is a high unmet need to reduce morbidity and mortality in patients with severe TR. During recent years, several transcatheter solutions have been studied. This review focuses on the transcatheter edge-to-edge repair of TR (TTVR) with respect to patient selection, the procedure, pre- and peri-procedural echocardiographic assessments and clinical outcomes. Furthermore, we highlight the current status of TTVR in the Netherlands and provide data from our initial experience at the University Medical Centre Groningen.

Transcatheter Leaflet Strategies for Tricuspid Regurgitation TriClip and CLASP

Since the recognition of the impact of significant tricuspid regurgitation on the clinical course and mortality, intensive efforts have been made in identifying and developing individually suitable and catheter-based therapy strategies to offer those often older and multimorbid patients at high surgical risk safe, feasible, and efficacious treatment options with justifiable risk. Up to now, transcatheter edge-to-edge repair with leaflet approximation devices such as TriClip (Abbott, Santa Clara, CA, USA) and PASCAL Implant System (Edwards Lifesciences, Irvine, CA, USA) have been evaluated best and several clinical trials could prove safety, feasibility, and efficacy of said devices leading to their recent CE mark. However, further randomized controlled trial are pending and necessary to evaluate their impact on clinical course and outcome in comparison to established treatment recommendations.

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.

Early Feasibility Study of Cardioband Tricuspid System for Functional Tricuspid Regurgitation: 30-Day Outcomes

OBJECTIVES

The study reports for the first time the 30-day outcomes of the first U.S. study with the Cardioband tricuspid valve reconstruction system for the treatment of functional tricuspid regurgitation (TR).

BACKGROUND

Increasing severity of TR is associated with progressively higher morbidity and mortality; however, treatment options for isolated significant disease are limited.

METHODS

In this single-arm, multicenter, prospective Food and Drug Administration-approved early feasibility study (EFS), 30 patients with severe or greater symptomatic functional TR were enrolled who were deemed candidates for transcatheter tricuspid repair with the Cardioband tricuspid system by the local heart team and multidisciplinary screening committee.

RESULTS

The mean patient age was 77 years, 80% were women, 97% had atrial fibrillation, 70% were in New York Heart Association functional class III to IV with mean left ventricular ejection fraction of 58%, and 27% had severe, 20% massive, and 53% torrential TR. Device success was 93% and all patients were alive at 30 days. Between baseline and 30 days, septolateral tricuspid annular diameter was reduced by 13% (p < 0.001), 85% of patients had ≥1 grade TR reduction and 44% had ≤moderate TR, 75% were in New York Heart Association functional class I to II (p < 0.001), and overall Kansas City Cardiomyopathy Questionnaire score improved by 16 points (p < 0.001).

CONCLUSIONS

In patients with severe symptomatic functional TR, this is the first study in the United States with the Cardioband tricuspid system for direct transcatheter annular reduction. This early feasibility study demonstrates high procedural feasibility with no 30-day mortality. There is significant reduction of functional TR with clinically significant improvements in functional status and quality of life. (Edwards Cardioband Tricuspid Valve Reconstruction System Early Feasibility Study; NCT03382457).

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.

Transcatheter Tricuspid Valve Intervention: Current Perspective

Tricuspid regurgitation (TR) adversely impacts both quality of life and long-term survival, which generates interest in therapeutic approaches to mitigate these effects. Historically, therapeutic options for TR were limited to surgical approaches, which are often complicated by significant morbidity and mortality in elderly patients with multiple comorbidities. This gap in therapeutic options led to the rapid evolution of transcatheter tricuspid valve intervention (TTVI), with a wide variety of approaches pursued and early results suggesting that TTVI improves clinical outcomes. Numerous strategies, including edge-to-edge repair, annular reduction, spacers, caval valve implantation, and transcatheter tricuspid valve replacement form the basis of TTVI today. In this review, the authors discuss the current state of each approach.

Tricuspid Regurgitation in Left Ventricular Systolic Dysfunction: Marker or Target?

Far from being historically considered a primary healthcare problem, tricuspid regurgitation (TR) has recently gained much attention from the scientific community. In fact, in the last years, robust evidence has emerged regarding the epidemiological impact of TR, whose prevalence seems to be similar to that of other valvulopathies, such as aortic stenosis, with an estimated up to 4% of people >75 years affected by at least moderate TR in the United States, and up to 23% among patients suffering from heart failure with reduced ejection fraction. This recurrent coexistence of left ventricular systolic dysfunction (LVSD) and TR is not surprising, considered the multiple etiologies of tricuspid valve disease. TR can complicate heart failure mostly as a functional disease, because of pulmonary hypertension (PH), subsequent to elevated left ventricular end-diastolic pressure, leading to right ventricular dilatation, and valve tethering. Moreover, the so-called "functional isolated" TR can occur, in the absence of PH, as a result of right atrial dilatation associated with atrial fibrillation, a common finding in patients with LVSD. Finally, TR can result as a iatrogenic consequence of transvalvular lead insertion, another frequent scenario in this cohort of patients. Nonetheless, despite the significant coincidence of these two conditions, their mutual relation, and the independent prognostic role of TR is still a matter of debate. Whether significant TR is just a marker for advanced left-heart disease, or a crucial potential therapeutical target, remains unclear. Aim of the authors in this review is to present an update concerning the epidemiological features and the clinical burden of TR in the context of LVSD, its prognostic value, and the potential benefit for early tricuspid intervention in patients affected by contemporary TR and LVSD.

Short-Term Clinical Outcomes of Transcatheter Tricuspid Valve Repair With the Third-Generation MitraClip XTR System

OBJECTIVES

The aim of this study was to assess 30-day outcomes of transcatheter edge-to-edge repair with the MitraClip XTR for significant tricuspid regurgitation (TR), relative to baseline coaptation gap sizes (CGS).

BACKGROUND

Transcatheter edge-to-edge repair using the MitraClip NT for patients with significant TR is safe and efficacious; the utility of the MitraClip XTR is unknown.

METHODS

Patients with significant, symptomatic TR treated at a single site between April 2018 and December 2019, with consent and with complete data, were included (n = 50). Baseline and 30-day echocardiograms were assessed by an echocardiography core laboratory. Patients were divided into 3 subgroups on the basis of site-assessed CGS: subgroup I (< 7 mm), subgroup II (7 to 10 mm), and subgroup III (>10 mm).

RESULTS

Technical success of the MitraClip XTR implantation was 100% (88% in the septal-anterior position) using a median of 2 clips (interquartile range: 1 to 2). At 30 days, single-leaflet detachment was noted in 3 patients (6%), with no instances of device embolization. TR was reduced by 1 grade in subgroup I and by 2 grades in subgroups II and III. New York Heart Association functional class was reduced by 1 class in all 3 subgroups. The 6-min walk distance increased in subgroup I (+115 m; p = 0.014) and subgroup II (+31.5 m; p = 0.028) but not subgroup III (+50 m; p = 0.999). A CGS of ≤8.4 mm was predictive of a reduction to moderate or less TR.

CONCLUSIONS

MitraClip XTR implantation is a safe, effective treatment for a wider range of CGS in patients with symptomatic, significant TR than prior device iterations. All patients showed improvement in New York Heart Association functional class, and those with CGS <10 mm also experienced improved functional capacity.

Tricuspid annulus cinching force under pulmonary hypertensive right ventricle conditions: An ex vivo study

This study investigates the force required to reduce or "cinch" the tricuspid annulus under elevated right ventricular pressures, commonly seen in patients with pulmonary hypertension. Tricuspid regurgitation affects 1.6 million Americans. Approximately 43% of patients who undergo tricuspid valve repair to correct tricuspid regurgitation will develop residual pulmonary hypertension, putting them at risk for developing increased right ventricle pressures. Previous studies have quantified the forces required to cinch the tricuspid annulus by only pressurizing the right ventricle, leaving out forces from the pressurized left ventricle and septal wall unaccounted for. This study pressurized both left and right ventricles of 10 porcine hearts to their normal physiological pressures of 110 mmHg and 30 mmHg respectively, then increased right ventricular pressures to mimic moderate and severe pulmonary hypertension. A suture was anchored around the free wall of the tricuspid annulus with the free end attached to a force transducer. The force transducer was mounted on a slider system which pulled the suture at regular intervals. The cinching force on the tricuspid annulus was quantified with each annular reduction by simulating peak systole condition in both ventricles. The data was compared with only the right ventricle pressurized as previous studies did. There were significant differences in required cinching forces with each increase in right ventricular pressure and between trials that pressurized both ventricles versus only the right ventricle, suggesting adoption of this physiologically improved protocol. We also found with increased cinching of the tricuspid annulus, notable changes occur in the mitral annulus.

Non-coaptation of an implanted caval valve leaflets for severe tricuspid regurgitation: Rethinking the concept of "Eustachian ridge?"

Severe symptomatic tricuspid regurgitation (TR) remains an undertreated disease. Multiple trans-catheter treatment options are currently under investigation. Transcatheter caval valve implantation (CAVI) has been utilized as a treatment option and aims at decreasing or eliminating the caval backflow that occurs in severe TR patients. Understanding challenges with this therapy is paramount. Hereby we present a CAVI case with resultant non-coaptation of valve leaflets in a patient with a prominent Eustachian ridge.

Transcatheter tricuspid valve implantation with the Cardiovalve system

Historically considered the 'forgotten valve', there has been increasing attention on the percutaneous transcatheter treatment of tricuspid regurgitation (TR). Prevalence of TR is high in the elderly population and prior studies have shown worse outcomes in patients with severe TR. Advances in transcatheter-based therapies have shed a new light in the treatment of TR and one such treatment option is tricuspid valve replacement with the Cardiovalve system. This device is approved as an early feasibility study in the US and also approved for clinical study in Germany, Italy and Switzerland. The Cardiovalve device is in the early stage of clinical studies and this article reviews the existing clinical data and future studies on percutaneous transcatheter treatment of severe TR.

New Percutaneous Options for Tricuspid Intervention: How to Identify the Good Clinical Candidate

The tricuspid valve has been neglected for a long time and severe tricuspid regurgitation (TR) was largely undertreated in the past due to a high operative risk. In the last years we observed the development of different less invasive percutaneous options to treat TR. Currently, percutaneous treatments are reserved for high-risk patients presenting with advanced stage disease by which time they are likely to derive a partial benefit at best. There is a limited evidence base, including no randomized trials, to guide the management strategy for severe TR. In the interim we feel that choosing the best device for the most appropriate clinical candidate and with an adequate timing (most probably an “earlier” timing) will be the key combination to improve early and late outcomes of percutaneous treatments.

Tricuspid Valve Annuloplasty Alters Leaflet Mechanics

Tricuspid valve regurgitation is associated with significant morbidity and mortality. Its most common treatment option, tricuspid valve annuloplasty, is not optimally effective in the long-term. Toward identifying the causes for annuloplasty's ineffectiveness, we have previously investigated the technique's impact on the tricuspid annulus and the right ventricular epicardium. In our current work, we are extending our analysis to the anterior tricuspid valve leaflet. To this end, we adopted our previous strategy of performing DeVega suture annuloplasty as an experimental methodology that allows us to externally control the degree of cinching during annuloplasty. Thus, in ten sheep we successively cinched the annulus and quantified changes to leaflet motion, dynamics, and strain in the beating heart by combining sonomicrometry with our well-established mechanical framework. We found that successive cinching of the valve enforced earlier coaptation and thus reduced leaflet range of motion. Additionally, leaflet angular velocity during opening and closing decreased. Finally, we found that leaflet strains were also reduced. Specifically, radial and areal strains decreased as a function of annular cinching. Our findings are critical as they suggest that suture annuloplasty alters the mechanics of the tricuspid valve leaflets which may disrupt their resident cells' mechanobiological equilibrium. Long-term, such disruption may stimulate tissue maladaptation which could contribute to annuloplasty's sub-optimal effectiveness. Additionally, our data suggest that the extent to which annuloplasty alters leaflet mechanics can be controlled via degree of cinching. Hence, our data may provide direct surgical guidelines.

Tricuspid valve diseases: Interventions on the forgotten heart valve

Over the past few decades, the tricuspid valve (TV) interventions have been relatively lower compared to other cardiac valvular disease in terms of pathophysiology and management, especially regarding surgical intervention and therapy. However, recent crucial advances in assessment and management of the TV disease have resulted in a renewed interest in the "forgotten valve." The medical treatment aims to cure the underlying disease and address the presentation of the right heart failure. Surgical interventions have proven to yield good outcomes for those for whom surgery is indicated. For those who are not suitable for surgery, transcatheter surgery may prove to be a suitable replacement. Best practice with regard to surgical techniques is still in question due to limited data. This has been slowing the introduction of transcatheter interventions into common practical guidelines. The aim of this literature review is to discuss new insights on the pathophysiology, diagnosis, and interventions of TV disease, highlighting the surgical management and emerging transcatheter therapies. In addition, this review will provide an overview of the current state of the literature surrounding TV interventions and providing suggestions for future directives.

Future Perspectives in Percutaneous Treatment of Tricuspid Regurgitation

Tricuspid regurgitation (TR) has a not negligible prevalence and its severity is correlated with poorer outcomes. However, surgical options are rarely offered to these patients because of their high surgical risk. Given that medical therapy plays a limited role in the management of these patients, there is an increasing clinical need for transcatheter treatment options. Although, transcatheter tricuspid valve interventions (TTVIs) are still at an early stage, emerging data suggests their clinical effectiveness and safety, with preliminary results highlighting the potential benefits of transcatheter treatments over medical therapy. In this review, we highlight the challenges and future directions of current and emerging technologies dedicated to the treatment of TR along with an analysis of the next steps required in future clinical trials and studies dedicated to the treatment of the forgotten valve.

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.

Unsolved questions in prophylactic tricuspid valve repair and the possible role of transcatheter tricuspid intervention

Tricuspid regurgitation progression after left-sided surgery and its correlation with worse postoperative and long-term outcomes is a highly debated topic. Some studies support prophylactic tricuspid repair based on annulus dimension rather than on tricuspid regurgitation severity only, while others are in favor of a more conservative management. Furthermore, the advent of percutaneous tricuspid valve intervention and its promising short-term outcomes has introduced a new factor to be taken into account on the tricuspid intervention decision-making process. We present a review on prophylactic tricuspid valve intervention, covering currently available data, as well as the role of transcatheter tricuspid valve intervention in this equation.

Tricuspid Regurgitation in Congestive Heart Failure: Management Strategies and Analysis of Outcomes

Tricuspid regurgitation is a notable aspect of congestive heart failure and is linked with worse outcomes if untreated. Functional tricuspid regurgitation commonly is seen in patients with heart failure, particularly in patients presenting for surgical management, such as those for mechanical cardiac assist device implantation. This review aims to study the published data related to the surgical management of tricuspid regurgitation in the cardiac surgical population comprehensively.

Transcatheter management of valvular regurgitation beyond the aortic valve (mitral - tricuspid valve): Literature overview and future perspectives

The growth of the available transcatheter treatment approaches for the mitral and tricuspid position was accompanied by important clinical trials and studies through the last years. The selection of appropriate candidates for transcatheter techniques requires significant insight into anatomical limitations of each patient undergoing clinical evaluation. Furthermore, technological characteristics of the available devices, and risks and benefits of each potential therapy, play the most important role in a physician's decision. This knowledge should be valuable to both interventional cardiologists and researchers. This paper aims to offer a concise overview of the technological advances in this field of Interventional Cardiology. Trials and studies announced at the major interventional cardiology congresses during 2018 and 2019 were systematically reviewed. Moreover, a literature search in PubMed for the same period identified an amount of publications eligible for inclusion, based on their relevance to the subject, and their potential impact on current guidelines of good clinical practice.

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.