Current state of transcatheter tricuspid valve repair

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.

Unique Aspects of Women's Valvular Heart Diseases: Impact for Diagnosis and Treatment

Valvular heart diseases (VHDs) are a major cause of cardiovascular morbidity and mortality worldwide. As degenerative and functional mechanisms represent the main etiologies in high-income countries are degenerative and functional, while in low income countries etiologie is mostly rheumatic. Although therapeutic options have evolved considerably in recent years, women are consistently diagnosed at later stages of their disease, are delayed in receiving surgical referrals, and exhibit worse postoperative outcomes, compared to men. This difference is a result of the historical underrepresentation of women in studies from which current guidelines were developed. However, in recent years, important research, including more female patients, has been conducted and has highlighted substantial sex-specific differences in the etiology, diagnosis, and treatment of VHDs. Systematic consideration of these sex-specific differences in VHD patients is crucial for providing equitable healthcare and optimizing clinical outcomes in both female and male patients. Hence, this review aims to explore implications of sex-specific particularities for diagnosis, treatment options, and outcomes in women with VHDs.

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).

A multifunctional soft robot for cardiac interventions

In minimally invasive endovascular procedures, surgeons rely on catheters with low dexterity and high aspect ratios to reach an anatomical target. However, the environment inside the beating heart presents a combination of challenges unique to few anatomic locations, making it difficult for interventional tools to maneuver dexterously and apply substantial forces on an intracardiac target. We demonstrate a millimeter-scale soft robotic platform that can deploy and self-stabilize at the entrance to the heart, and guide existing interventional tools toward a target site. In two exemplar intracardiac procedures within the right atrium, the robotic platform provides enough dexterity to reach multiple anatomical targets, enough stability to maintain constant contact on motile targets, and enough mechanical leverage to generate newton-level forces. Because the device addresses ongoing challenges in minimally invasive intracardiac intervention, it may enable the further development of catheter-based interventions.

Future prospects in the tissue engineering of heart valves: a focus on the role of stem cells

INTRODUCTION

Heart valve disease is a growing burden on the healthcare system. Current solutions are insufficient for young patients and do not offer relief from reintervention. Tissue engineered heart valves (TEHVs) offer a solution that grows and responds to the native environment in a similar way to a healthy valve. Stem cells hold potential to populate these valves as a malleable source that can adapt to environmental cues.

AREAS COVERED

This review covers current methods of recapitulating features of native heart valves with tissue engineering through use of stem cell populations with in situ and in vitro methods.

EXPERT OPINION

In the field of TEHVs, we see a variety of approaches in cell source, biomaterial, and maturation methods. Choosing appropriate cell populations may be very patient specific; consistency and predictability will be key to long-term success. In situ methods are closer to translation but struggle with consistent cellularization. In vitro culture requires specialized methods but may recapitulate native valve cell populations with higher fidelity. Understanding how cell populations react to valve conditions and immune response is vital for success. Detrimental valve pathologies have proven to be difficult to avoid in early translation attempts.

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.

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.

Tricuspid valve regurgitation: current diagnosis and treatment

Tricuspid regurgitation (TR) is present in 1.6 million individuals in the United States and 3.0 million people in Europe. Functional TR, the most common form of TR, is caused by cardiomyopathies, LV valve disease, or pulmonary disease. The five-year survival with severe TR and HFrEF is 34%. Echocardiography can assess the TR etiology/severity, measure RA and RV size and function, estimate pulmonary pressure, and characterize LV disease. Management includes diuretics, ACE inhibitors, and aldosterone antagonists. Surgical annuloplasty or valve replacement should be considered in patients with progressive RV dilatation without severe LV dysfunction and pulmonary hypertension. Transcatheter repair/replacement is possible in patients with a LVEF <40%, dilated annuli, and impaired RV function. The diagnosis and treatment of TR, including coaptation, annuloplasty devices and prosthetic valves, success rates, morbidity/mortality, and trials are discussed. Transcatheter tricuspid valve repair/replacement is an emerging therapy for high-risk patients with TR who would otherwise have a dismal clinical prognosis.

Transcatheter treatment of severe tricuspid regurgitation

PURPOSE OF REVIEW

Severe tricuspid regurgitation is a commonly prevalent valvular heart disease that is an independent adverse prognostic marker. However, the majority of patients with tricuspid regurgitation are managed medically; isolated tricuspid valve surgery is rarely performed, partly owing to high associated in-hospital mortality. Therefore, several transcatheter tricuspid valve interventions (TTVIs) that have been developed over the last few years to address this unmet clinical need.

RECENT FINDINGS

The early experience with TTVI has shown that most devices can be safely implanted with excellent rates of technical success and acceptable safety outcomes. Most TTVI recipients have significant improvement in tricuspid regurgitation severity, functional class, and quality of life. Recent retrospective data also suggest mortality benefit of TTVI compared with medical management. There are several issues that need to be addressed prior to widespread adoption of TTVI, including more effective tricuspid regurgitation reduction and need for longer term efficacy data.

SUMMARY

TTVI has emerged as an attractive treatment option for management of high-risk patients with tricuspid regurgitation. In this review, we will discuss the anatomical considerations specific to tricuspid valve, patient selection, preprocedure planning, and summarize the current evidence and future perspectives on TTVI.

A Single-opening&closing Valve Tester for Direct Measurement of Closing Volume of the Heart Valve

PURPOSE

The objective of this study was to develop a novel single opening&closing pulsatile flow in-vitro valve tester for direct measurement of closing volume of the heart valve.

METHODS

A single opening&closing valve tester was composed of a piston pump, valve mounting chamber, reservoir, measurement and control system. The piston pump was used to drive a valve to open and close with dictated flow which comprised three phases of accelerated, constant, and decelerated flow with six slopes. A high speed camera was used to record valve opening and closing images. Two pressure transducers across the tested valve were used to capture the ending time of valve closing which was verified by the high-speed photography. The closing time was measured and closing volume was calculated with a piston displacement volume during valve closing. A tilting disc valve and porcine mitral valve were tested.

RESULTS

There was a big difference in flowrate between the Transonic flowmeter and piston pump. The heart valve opened and closed under the dictated flow driven by the piston pump. The transvalvular pressure was minor during valve opening and then increased sharply during valve closing. The closing time varied approximately linearly with the slope of the decelerated flow and was comparable between the two methods by the transvalvular pressure and high-speed photography. The closing volumes did not change much with the slope of the decelerated flow and were 7.0 ± 1.0 and 14.0 ± 1.5 mL for the tilting disc valve and mitral valve, respectively.

CONCLUSION

Pulsatile flow is challenging to the flowmeter. A novel single opening&closing pulsatile flow in-vitro valve tester for the heart valve has successfully been developed and can be used to simulate and evaluate the opening and closing hemodynamics of the heart valve. The tester can be used to measure valve closing volume and time accurately with a standardized testing protocol free from effect of other components such as the resistance, compliance units and auxiliary valve in the continuous pulsatile flow valve tester.

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.

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.

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.