First-in-Man Experience of a Novel Transcatheter Repair System for Treating Severe Tricuspid Regurgitation

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.

Lead management in patients undergoing percutaneous tricuspid valve replacement or repair: a 'heart team' approach

Clinically significant tricuspid regurgitation (TR) has historically been managed with either medical therapy or surgical interventions. More recently, percutaneous trans-catheter tricuspid valve (TV) replacement and tricuspid trans-catheter edge-to-edge repair have emerged as alternative treatment modalities. Patients with cardiac implantable electronic devices (CIEDs) have an increased incidence of TR. Severe TR in this population can occur for multiple reasons but most often results from the interactions between the CIED lead and the TV apparatus. Management decisions in patients with CIED leads and clinically significant TR, who are undergoing evaluation for a percutaneous TV intervention, need careful consideration as a trans-venous lead extraction (TLE) may both worsen and improve TR severity. Furthermore, given the potential risks of 'jailing' a CIED lead at the time of a percutaneous TV intervention (lead fracture and risk of subsequent infections), consideration should be given to performing a TLE prior to a percutaneous TV intervention. The purpose of this 'state-of-the-art' review is to provide an overview of the causes of TR in patients with CIEDs, discuss the available therapeutic options for patients with TR and CIED leads, and advocate for including a lead management specialist as a member of the 'heart team' when making treatment decisions in patients TR and CIED leads.

Treatment of severe tricuspid regurgitation induced by permanent pacemaker lead: Transcatheter tricuspid valve replacement with the guidance of 3-dimensional printing

Background

Lead-induced tricuspid regurgitation is one of the complications after permanent pacemaker implantation (PPI) and refers to tricuspid regurgitation (TR) caused by the lead in the right ventricle (RV).

Objectives

To study the clinical characteristics of severe TR after PPI and the effect of transcatheter tricuspid valve replacement (TTVR) with the guidance of 3-dimensional (3D) printing.

Methods

This study was a single-center, descriptive study. Six patients with severe TR after PPI were enrolled in Xijing Hospital from January 2020 to May 2020. Before TTVR, the 3D printed tricuspid valve (TV) model was used for evaluation in the bench test. LuX-Valve was implanted under the guidance of TEE and x-ray fluoroscopy, and all patients underwent transatrial access. Six patients' data were collected at baseline, before discharge, and 6 months, 1 year and 2 years after TTVR.

Results

The LuX-Valve was successfully implanted in 6 patients, TR was significantly reduced to ≤2+, and no deaths or cardiopulmonary bypass occurred during procedures. Three cases were caused by TV expansion: Patient #4 had TR caused by lead adhesion to TV, Patient #2 had TR caused by lead winding, and Patient #6 had TR caused by lead impingement on TV. During the 2-year follow-up, TTE revealed that 5 patients had no/trace regurgitation, and one patient (Patient #5) had mild regurgitation. All 6 patients (100.0%) reached primary endpoints.

Conclusion

TTVR guided by 3D printing is safe and effective in the treatment of severe TR associated with permanent pacemaker lead, providing prospects and possibilities for the precise treatment of TV-related diseases.Clinical Trial Registration: ClinicalTrials.gov Protocol Registration System (NCT02917980).

Safety, efficacy, and clinical outcomes of transcatheter tricuspid valve replacement: One-year follow-up

Objective

The aim was to evaluate the safety and efficacy of TTVR in patients with severe TR at the 1-year follow-up.

Materials and methods

This project was a single-center, observational study. From September 2020 to May 2021, 15 patients with severe or extremely severe TR at high risk of traditional surgery were enrolled. All patients had preoperative imaging assessments to evaluate the tricuspid valve and the anatomy of the right heart. All patients were planned to treated with the LuX-Valve (Ningbo Jenscare Biotechnology, Ningbo, China). The LuX-Valve was implanted under the intraoperative guidance of TEE and X-ray fluoroscopy. Data were collected at baseline, before discharge, and at 30 days, 6 months, and 1 year postoperatively.

Results

The LuX-Valves were successfully implanted in all 15 patients. TR was significantly reduced to ≤ 2 +. One patient died on postoperative day 12 of a pulmonary infection that was considered unrelated to the procedures or the devices. The remaining 14 patients (100.0%) reached the primary end point. One patient (7.1%) was rehospitalized during 1-year follow-up because of device thrombosis. The number of patients who survived at 1 year with New York Heart Association (NYHA) functional class II was higher than that before TTVR (11/14 vs. 0/15, P = 9.11 × 10–4). Patients with peripheral edema and ascites decreased from 100.0 to 46.7% at baseline to 28.6% and 14.3% at 1 year (P = 1.57 × 10–3 and 2.53 × 10–2).

Conclusion

TTVR is associated with RV remodeling, increased cardiac output, and improvement in NYHA functional class. Using the LuX-Valve for TTVR to treat patients with severe TR is a feasible and relatively safe method with reliable clinical results. Further studies are needed to determine long-term outcomes.

Indications, Limitations, and Development of Tricuspid Valve Interventions in Adults

Tricuspid regurgitation is associated with excessive mortality and poor outcomes regardless of the cause and associated comorbidities. Despite this clear association with mortality, tricuspid valve diseases remain undertreated. Tricuspid valve surgery, either repair or replacement, has shown little detectable survival benefit. Transcatheter tricuspid valve interventions have emerged as a less invasive approach to tricuspid valve diseases. They can be categorised into coaptation devices, annuloplasty devices, transcatheter tricuspid valve replacement, heterotopic caval valve implantation, and tricuspid valve-in-valve. Despite the late referral and the patient's profile, results remain fairly acceptable at least in the short term, with good procedural device success, excellent safety profile, and sustained reduction of tricuspid regurgitation for up to 1 year. Because results are limited to the mid-term, transcatheter tricuspid valve intervention durability will need to be established before broader adoption of these technologies.

Transcatheter Double Valve Replacement to Treat Aortic Stenosis and Severe Tricuspid Regurgitation with 3D Printing Guidance after Mechanical Mitral Valve Replacement

Background: Transcatheter treatments of tricuspid regurgitation (TR) have been emerging as alternatives for high-risk patients. In contrast to the immobilization of the common transcatheter tricuspid device, using a radial force-independent stent valve device at the native tricuspid annular site has several distinct advantages. Case summary: A 76-year-old patient with renal insufficiency who underwent mechanical mitral valve replacement in 2001 and transcatheter aortic valve replacement in 2021 due to severe aortic stenosis presented with chest pain and shortness of breath. Echocardiography suggested that the flow velocities of the mitral mechanical valve and aortic prosthetic valve were both within the normal range, with no significant paravalvular regurgitation; the tricuspid valve exhibited massive regurgitation (VMAX 258 cm/s, PGMAX 27 mmHg). Due to the high surgical risk, we simulated the procedure with a three-dimensional (3D)-printed model and performed transcatheter tricuspid valve replacement using a LuX-Valve (Ningbo Jenscare Biotechnology Co., Ningbo, China). Discussion: We describe transcatheter tricuspid valve replacement using the LuX-Valve and preprocedural guidance with 3D printing. Postprocedural TR was significantly reduced, indicating that 3D printing plays an important role in preprocedural guidance and that the LuX-Valve was safe and practicable for tricuspid valve replacement.

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.

Clinical and Echocardiographic Outcomes of Transcatheter Tricuspid Valve Interventions: A Systematic Review and Meta-Analysis

Background

Medically managed tricuspid regurgitation (TR) has detrimental outcomes. Transcatheter tricuspid valve interventions (TTVIs) represent an alternative to surgery in high-risk patients; however, only early experiences exist.

Aim

The aim of this study was to analyze the clinical and echocardiographic outcomes of TTVI.

Methods

MEDLINE, ISI Web of Science, and SCOPUS databases were searched for studies published up to June 2021. Studies reporting data on outcome post-TTVIs were included. This study was designed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) requirements. The primary endpoint was all-cause mortality at 30-day and 1-year post-TTVI.

Results

Out of 2,718 studies, 27 were included. Notably, 30-day and 1-year all-cause mortalities were 5% (95% confidence interval [CI]: 4–8%, p < 0.001) and 25% (95% CI: 12–45%, p = 0.016). Procedural success was associated with a 58% risk reduction in 1-year mortality vs. lack thereof (odds ratio 0.42, 95% CI: 0.27–0.66, p < 0.001). TTVI is associated with a significant reduction in TR severity (TR EROA, mean difference [MD] 0.31 cm²; 95% CI: 0.23–0.39 cm², p < 0.001; regurgitant volume, MD 23.54 ml; 95% CI: 17.4–29.68 ml, p = 0.03) and increase in forward stroke volume (FSV, MD 3.98 ml; 95% CI: 0.11–7.86 ml, p = 0.04).

Conclusion

TTVI significantly reduces TR severity and increases FSV and is associated with improved survival at 1 year compared with patients without procedural success. Long-term outcomes compared with medical therapy await the results of ongoing pivotal trials; nonetheless, TTVIs appear to be a promising alternative to surgery for TR.

Transcatheter tricuspid valve intervention techniques and procedural steps for the treatment of tricuspid regurgitation: a review of the literature

Severe tricuspid regurgitation (TR) is an undertreated common pathology associated with significant morbidity and mortality. Classically, surgical repair or valve replacement were the only therapeutic options and are associated with up to 10% postprocedural mortality. Transcatheter tricuspid valve interventions are a novel and effective therapeutic option for the treatment of significant TR. Several devices have been developed with different mechanisms of action. They are classified as annuloplasty devices, replacement devices, caval valve implantation and coaptation devices. In this review, we provide a step-by-step description of the procedural steps and techniques of every device along with video support.

Transcatheter Tricuspid Valve Therapy: From Anatomy to Intervention

Nowadays, severe symptomatic tricuspid regurgitation (TR) affects millions of persons worldwide. However, the benefit of surgical correction of isolated secondary TR remains controversial because of the increased risk of periprocedural mortality and morbidity. In recent years, novel transcatheter tricuspid valve interventions (TTVI) were developed to treat TR, so that TTVI is currently considered in symptomatic, inoperable, anatomically eligible patients. TTVI can be divided into these five domains: edge-to-edge leaflet repair, tricuspid annuloplasty, caval implants, spacer, and total valve replacement. Each transcatheter intervention needs specific imaging protocols for assessing the anatomical feasibility and consequentially predicting the procedural success. This review summarizes the available multimodality imaging tools for screening patients with TR, and identifies anatomical characteristics to choose the best option for the patient.

Caval Valve Implantation

Transcathetertherapy has expanded the treatment options for patients with heart valve disease. Interventional therapy for aortic, mitral, and pulmonic valve disease is well established; however, catheter-based approaches to tricuspid regurgitation (TR) are still in early stages of development. For some of the interventional concepts to TR, including the edge-to-edge-repair, transcatheter annuloplasty, the tricuspid spacer, and caval valves, procedural feasibility and favorable early clinical outcome have been demonstrated in small compassionate case series. This article reviews the pathophysiological background and current evidence for caval valve implantation and examines the potential role of this approach for the treatment of severe TR.

Twelve-month outcomes of the LuX-Valve for transcatheter treatment of severe tricuspid regurgitation

BACKGROUND

Severe functional tricuspid regurgitation is associated with adverse clinical outcomes. Conventional surgical risk for patients with advanced tricuspid regurgitation stage is high. Alternative approaches are therefore required.

AIMS

The purpose of this study was to investigate the feasibility, technical details, and midterm outcomes of implantation of a novel radial force-independent orthotopic transcatheter tricuspid valve -the LuX-Valve- in patients with severe functional tricuspid regurgitation.

METHODS

The implantations of the LuX-Valve were performed in six patients with left-sided valvular surgery and secondary massive tricuspid regurgitation. The anatomy of the tricuspid valve and right heart measurements were evaluated by echocardiography and computed tomography in all patients. Conventional right ventricular (RV) function parameters and RV global longitudinal strain were obtained at baseline and 12-month follow-up. LuX-Valve implantation was performed under the guidance of digital subtraction angiography and transoesophageal echocardiography.

RESULTS

All patients had successful implantations of LuX-Valves through the right atrium with a substantial reduction in the degree of tricuspid regurgitation. Although one patient with moderate paravalvular leakage died because of right heart failure during three-month follow-up, the five patients who lived had no significant paravalvular leakage, and displayed significant improvements in mean transvalvular gradient, right heart sizes, conventional RV function indices and RV global longitudinal strain, and a reduction in New York Heart Association Functional Class during 12-month follow-up.

CONCLUSIONS

Transcatheter tricuspid valve replacement with the LuX-Valve was feasible and safe for patients with severe functional tricuspid regurgitation. This strategy seems a promising treatment option for patients at high surgical risk.

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.

Renal and hepatic function of patients with severe tricuspid regurgitation undergoing inferior caval valve implantation

Due to progressive abdominal-venous congestion severe tricuspid regurgitation (TR) is a common cause of cardiorenal and cardiohepatic syndrome. We initiated the TRICAVAL study to compare interventional valve implantation into the inferior vena cava (CAVI) versus optimal medical therapy (OMT) in severe TR. In the present subanalysis, we aimed to evaluate the effects of CAVI on clinical signs of congestion, renal and hepatic function. TRICAVAL was an investigator-initiated, randomized trial. Twenty-eight patients with severe TR were randomized to OMT or CAVI using an Edwards Sapien XT valve. Probands who completed the 3-month follow-up (CAVI [n = 8], OMT [n = 10]) were evaluated by medical history, clinical examination, and laboratory testing at baseline, 3 and 12 months. After 3 months, the CAVI group exhibited a significant reduction of body weight (from 80.7 [69.0–87.7] kg to 75.5 [63.8–84.6] kg, p < 0.05) and abdominal circumference (from 101.5 ± 13.8 cm to 96.3 ± 15.4 cm, p ≤ 0.01) and a trend to lower doses of diuretics compared to OMT. Renal and hepatic function parameters did not change significantly. Within a short-term follow-up, CAVI led to an improvement of clinical signs of venous congestion and a non-significant reduction of diuretic doses compared to OMT.

Single-Barrel, Double-Barrel, and Fenestrated Endografts to Facilitate Transcatheter Pulmonary Valve Replacement in Large RVOT

OBJECTIVES

The aim of this study was to test the hypothesis that narrowing the landing zone using commercially available endografts would enable transcatheter pulmonary valve replacement (TPVR) using commercially available transcatheter heart valves.

BACKGROUND

TPVR is challenging in an outsized native or patch-repaired right ventricular outflow tract (RVOT). Downsizing the RVOT for TPVR is currently possible only using investigational devices. In patients ineligible because of excessive RVOT size, TPVR landing zones were created using commercially available endografts.

METHODS

Consecutive patients with native or patch-repaired RVOTs and high or prohibitive surgical risk were reviewed, and this report describes the authors' experience with endograft-facilitated TPVR (EF-TPVR) offered to patients ineligible for investigational or commercial devices. All EF-TPVR patients were surgery ineligible, with symptomatic, severe pulmonary insufficiency, enlarged RVOTs, and severe right ventricular (RV) enlargement (>150 ml/m²). TPVR and surgical pulmonary valve replacement (SPVR) were compared in patients with less severe RV enlargement.

RESULTS

Fourteen patients had large RVOTs unsuitable for conventional TPVR; 6 patients (1 surgery ineligible) received investigational devices, and 8 otherwise ineligible patients underwent compassionate EF-TPVR (n = 5 with tetralogy of Fallot). Three strategies were applied on the basis of progressively larger RVOT size: single-barrel, in situ fenestrated, and double-barrel endografts as required to anchor 1 (single-barrel and fenestrated) or 2 (double-barrel) transcatheter heart valves. All were technically successful, without procedure-related, 30-day, or in-hospital deaths. Two late complications (stent obstruction and embolization) were treated percutaneously. One patient died of ventricular tachycardia 36 days after EF-TPVR. Compared with 48 SPVRs, RV enlargement was greater, but 30-day and 1-year mortality and readmission were no different. The mean transvalvular pressure gradient was lower after EF-TPVR (3.8 ± 0.8 mm Hg vs. 10.7 ± 4.1 mm Hg; p < 0.001; 30 days). More than mild pulmonary insufficiency was equivalent in both (EF-TPVR 0.0% [n = 0 of 8] vs. SPVR 4.3% [n = 1 of 43]; p = 1.00; 30 days).

CONCLUSIONS

EF-TPVR may be an alternative for patients with pulmonic insufficiency and enlarged RVOTs ineligible for other therapies.

Transcatheter Treatment of Secondary Tricuspid Regurgitation With Direct Annuloplasty: Results From a Multicenter Real-World Experience

[Figure: see text].

Outcomes of transcatheter tricuspid valve intervention by right ventricular function: a multicentre propensity-matched analysis

BACKGROUND

Tricuspid regurgitation (TR) has a poor prognosis and limited treatment options and is frequently accompanied by right ventricular (RV) dysfunction. Transcatheter tricuspid valve interventions (TTVI) to reduce TR have been shown to be safe and feasible with encouraging early results. Patient selection for TTVI remains challenging, with the role of right ventricular (RV) function being unknown.

AIMS

The aims of this study were 1) to investigate survival in a TTVI-treated patient population and a conservatively treated TR population, and 2) to evaluate the outcome of TTVI as compared to conservative treatment stratified according to the degree of RV function.

METHODS

We studied 684 patients from the multicentre TriValve cohort (TTVI cohort) and compared them to 914 conservatively treated patients from two tertiary care centres. Propensity matching identified 213 pairs of patients with severe TR. As we observed a non-linear relationship of RV function and TTVI outcome, we stratified patients according to tricuspid annular plane systolic excursion (TAPSE) to preserved (TAPSE >17 mm), mid-range (TAPSE 13-17 mm) and reduced (TAPSE <13 mm) RV function. The primary outcome was one-year all-cause mortality.

RESULTS

TTVI was associated with a survival benefit in patients with severe TR when compared to matched controls (one-year mortality rate: 13.1% vs 25.8%; p=0.031). Of the three RV subgroups, only in patients with mid-range RV function was TTVI associated with an improved survival (p log-rank 0.004). In these patients, procedural success was associated with a reduced hazard ratio for all-cause mortality (HR 0.22; 95% CI: 0.09, 0.57).

CONCLUSIONS

TTVI is associated with reduced mortality compared to conservative therapy and might exert its highest treatment effect in patients with mid-range reduced RV function.

Multi-Modality Imaging for Interventions in Tricuspid Valve Disease

Several studies have demonstrated that severe tricuspid regurgitation (TR) has a significant negative impact on morbidity and mortality. Nowadays, several therapeutic options to treat TR are available and patients at high surgical risk can also be treated with transcatheter procedures. For the management of patients with TR, an accurate assessment of the tricuspid valve and its surrounding structures is therefore of crucial importance and has gained significant interest in the medical community. Different imaging modalities can provide detailed information on the tricuspid valve apparatus, right ventricle, right atrium, and coronary circulation which are fundamental to define the timing and anatomic suitability of surgical and percutaneous procedures. The present review illustrates the role of 2D and 3D echocardiography, cardiac magnetic resonance, and multidetector row computed tomography for the assessment of the tricuspid valve and right heart with a particular focus on the data needed for planning and guiding interventional procedures.

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.

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.

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 Tricuspid Valve Intervention: Coaptation Devices

Transcatheter tricuspid valve intervention (TTVI) has recently emerged as an alternative for the treatment of severe tricuspid regurgitation (TR). Multiple percutaneous devices have been developed in the last decade with promising early results. Among them, the coaptation devices are designed to reduce TR severity by valve leaflet plication or occupying the regurgitant orifice with a spacer. To date, the MitraClip/TriClip devices (Abbott, Santa Clara, CA, USA), the PASCAL system (Edwards Lifesciencies, Irvine, CA, USA), and the FORMA device (Edwards Lifesciencies, Irvine, CA, USA) have been used as coaptation devices for treating severe TR. The present document aimed to review the clinical evidence on coaptation devices in the field of TTVI, describing its design characteristics, main procedural steps, and early and mid-term outcomes.

Long-Term Outcomes of the FORMA Transcatheter Tricuspid Valve Repair System for the Treatment of Severe Tricuspid Regurgitation: Insights From the First-in-Human Experience

OBJECTIVES

To evaluate the long-term (≥2 years) outcomes following transcatheter tricuspid valve repair (TTVr) with the FORMA Transcatheter Tricuspid Valve Repair System (Edwards Lifesciences, Irvine, California).

BACKGROUND

Scarce data exist on long-term outcomes following TTVr.

METHODS

This multicenter experience included patients with severe tricuspid regurgitation (TR) who underwent TTVr with the FORMA system at 4 centers under a compassionate clinical use program. Data were collected at baseline, 30 days, and 1 year, and yearly thereafter.

RESULTS

Nineteen patients (76 ± 9 years of age, 74% women, mean EuroSCORE II [European System for Cardiac Operative Risk Evaluation] 9.2 ± 5.6%) with functional TR were included. Procedural success was achieved in 17 (89%) patients and there were no cases of 30-day mortality. At a median follow-up of 32 (interquartile range: 24 to 36) months, 4 (24%) patients had died (3 from terminal heart failure, 1 from sepsis) and 3 (18%) patients required rehospitalization for heart failure. There was 1 device-related thrombosis and 1 pulmonary embolism, both in the setting of subtherapeutic oral anticoagulation. Less than severe TR was observed at echocardiography in 67% of patients at the 2- to 3-year follow-up. Among 15 successfully implanted patients with at least 24-month follow-up, significant improvements in New York Heart Association functional class (p < 0.001), 6-min walk test (+54 m; p = 0.016) and Kansas City Cardiomyopathy Questionnaire score (+16 points; p = 0.016) were observed, compared with baseline.

CONCLUSIONS

TTVr using the FORMA system showed favorable long-term safety profile in high-surgical-risk patients, with sustained functional improvement and acceptable TR reduction up to 3 years.

Refining Severe Tricuspid Regurgitation Definition by Echocardiography with a New Outcomes-Based "Massive" Grade

BACKGROUND

Current echocardiographic guidelines recommend that tricuspid regurgitation (TR) severity be graded in three categories, following assessment of specific parameters. Findings from recent trials have shown that the severity of TR frequently far exceeds the current definition of severe. We postulated that a grading approach that emphasizes outcomes could be useful to identify patients with severe TR at increased risk of mortality.

METHODS

We identified 284 patients with echocardiograms demonstrating severe functional TR, defined as vena contracta (VC) ≥ 0.7 cm. Demographics and mortality data were obtained from the medical records. Patients were divided into study (n = 122 patients with three-dimensional images) and validation (n = 162) cohorts. The VC was measured in both the right ventricular (RV) inflow and apical four-chamber views and averaged. For the study cohort, tricuspid annular, RV end-diastolic (basal, mid, long axis) dimensions, tricuspid leaflet tenting height and area, RV free-wall longitudinal strain, and RV volumes were measured from two- and three-dimensional data sets. A K-partition algorithm was used in the study cohort to derive a mortality-related cutoff VC value, above which TR was termed "massive." The ability of this VC cutoff to identify patients at greater mortality risk was then tested in the validation cohort using Kaplan-Meier survival analysis.

RESULTS

In the study cohort, VC > 0.92 cm (massive TR) was optimally associated with worse survival. Tricuspid annular and RV size were larger in the massive group (P < .05), while there were no significant differences in demographics between the TR groups. Importantly, in the independent validation cohort, the above VC cutoff also correlated with increased mortality in the massive group (log-rank P < .05).

CONCLUSIONS

Among patients traditionally defined as having severe TR, a subset exists with massive TR, resulting in greater adverse RV remodeling and increased mortality. These patients may derive the greatest benefit from emerging percutaneous therapies.

Impact of inferior caval valve implantation on severity of tricuspid regurgitation and right heart function

AIMS

Severe tricuspid regurgitation (TR) is a common finding in heart failure patients and associated with increased mortality. New interventional therapeutic options are needed as many heart failure patients are unfit for surgery. The TRICAVAL study compared valve implantation into the inferior vena cava (CAVI) with optimal medical therapy (OMT) in patients with severe TR. Here, we report details on the impact of CAVI on TR severity as well as right heart function and morphology.

METHODS AND RESULTS

We randomized 28 patients with severe TR to CAVI (n = 14) with transfemoral implantation of an Edwards Sapien XT valve into the inferior vena cava or OMT (n = 14). Inclusion and exclusion criteria were based on anatomical and clinical parameters. Echocardiographic measurements were performed at baseline, at the first postoperative day and one, three, and twelve months after randomization. As proof of concept of an effective sealing of the inferior vena cava, we detected a significant decrease in systolic hepatic vein reflux volume (11.0 [6.2-21.9] mL vs 3.5 [0.6-8.5] mL, P = .016) and hepatic vein diameter (11.5 [10.0-14.8] mm vs 10.0 [9.3-11.8] mm, P = .034) at thirty-day follow-up. However, CAVI had no significant impact on TR, cardiac function, and morphology.

CONCLUSIONS

Caval valve implantation significantly reduced systolic reflux into the hepatic veins but was not associated with an improvement in cardiac function, morphology, or TR severity.

Advances in transcatheter mitral and tricuspid therapies

BACKGROUND

While rheumatic mitral stenosis has been effectively treated percutaneously for more than 20 years, mitral and tricuspid regurgitation treatment appear as a contemporary unmet need. The advent of transcatheter therapies offer new treatment options to often elderly and frail patients at high risk for open surgery. We aimed at providing an updated review of fast-growing domain of transcatheter mitral and tricuspid technology.

MAIN BODY

We reviewed the existing literature on mitral and tricuspid transcatheter therapies. Mitraclip is becoming an established therapy for secondary mitral regurgitation in selected patients with disproportionately severe regurgitation associated with moderate left ventricle dysfunction. Evidence is less convincing for primary mitral regurgitation. Transcatheter mitral valve replacement is a promising emerging alternative to transcatheter repair, for secondary as well as primary mitral regurgitation. But further development is needed to improve delivery. Transcatheter tricuspid intervention arrives late after similar technologies have been developed for aortic and mitral valves and is currently at its infancy. This is likely due in part to previously under-recognized impact of tricuspid regurgitation on patient outcomes. Edge-to-edge repair is the most advanced transcatheter solution in development. Data on tricuspid annuloplasty and replacement is limited, and more research is warranted.

CONCLUSION

The future appears bright for transcatheter mitral therapies, albeit their place in clinical practice is yet to be clearly defined. Tricuspid transcatheter therapies might address the unmet need of tricuspid regurgitation treatment.

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.

Optimizing Cardiac CT Protocols for Comprehensive Acquisition Prior to Percutaneous MV and TV Repair/Replacement

Clinical trials of transcatheter mitral valve and tricuspid valve repair and replacement devices have begun in earnest, with the ultimate goal of providing definitive, nonsurgical treatment for the millions of patients with severe, symptomatic regurgitation, many of whom are too high risk or inoperable for a surgical approach. Computed tomography (CT) angiography offers the potential for detailed anatomic assessment in this patient population, but its optimal implementation for patients with mitral and tricuspid disease requires patient-centered protocol specification reflecting the goal of the scan, an understanding of complex anatomy and pathophysiology, and particulars of CT scanner capabilities. In this paper, the need for new interventional approaches to mitral and tricuspid valve disease is discussed, followed by a detailed review of how to perform a high-quality CT angiography examination, taking into consideration scanner- and patient-specific variables when preparing a pre-mitral or tricuspid protocol. The many possible clinical challenges affecting the performance of cardiac and vascular CT angiography for pre-procedure mitral and tricuspid repair/replacement are reviewed and specific tips, trouble-shooting approaches, and recommendations are provided for how to conduct the best-quality study, be it at an experienced imaging center with the most advanced scanner or at a novice center using an earlier generation CT platform.

The FORMA Repair System

Significant tricuspid valve disease affects many patients with left-sided heart disease. Concomitant tricuspid valve surgery for at least moderate tricuspid insufficiency is undertaken far less frequently at the time of left-sided heart surgery. The burden of residual tricuspid disease in high-surgical-risk patients has spawned the evolution of several percutaneous treatment options. A dedicated percutaneously delivered tricuspid Spacer device (FORMA Repair System) has been developed and trialed in humans. This system anchors a Spacer to reduce the regurgitant orifice area, thereby providing a surface for valve leaflet coaptation. This article provides an overview of the FORMA Repair System to date.

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.

Treatment of Tricuspid Regurgitation With the FORMA Repair System

Background: Tricuspid regurgitation (TR) is common and undertreated as the risk of surgery is high in this patient population. Transcatheter devices offer treatment with a lower procedural risk. The FORMA Tricuspid Valve Therapy system (Edwards Lifesciences) will be reviewed here. Device Description: The system combines a spacer placed in the regurgitant orifice and a rail, over which the spacer is delivered, that is anchored to the endocardial surface of the RV. The spacer provides a surface for leaflet coaptation. Outcomes: Eighteen compassionate care patients and 29 patients included in the US EFS trial are reviewed. Patients were elderly (76 years) and high risk (Euroscore 2 was 9.0 and 8.1%, respectively). There were 2 procedural failures in both groups. Mortality at 30 days was 0% in the compassionate group and 7% in the EFS trial. TR was reduced in both groups; 2D/3D EROA 2.1 ± 1.8 to 1.1 ± 0.9 cm² in the EFS trial and vena contracta width 12.1 ± 3.3 to 7.1 ± 2.2 mm. Symptomatic improvement was seen in both groups; the proportion of patients in NYHA class III/IV decreased from 84 to 28% at 30 days in the EFS group, and from 94 to 21% at 1 year, in the compassionate group. Conclusions: Reduction of TR with FORMA system is feasible and sustained. Despite residual TR post-procedure, the significant relative reduction in TR severity contributes to substantial clinical improvements in patients with a FORMA device in place.

Prevalence of moderate-to-severe TR suitable for percutaneous intervention in TTE patients

Moderate-to-severe tricuspid regurgitation is associated with higher mortality and morbidity yet remains significantly undertreated. The reasons for this are complex but include a higher operative mortality for patients undergoing isolated tricuspid valve surgery. This study sought to determine the prevalence of patients with moderate-to-severe tricuspid regurgitation and identify those who could be potentially suitable for percutaneous tricuspid valve intervention by screening patients referred for transthoracic echocardiography (ECHO) at a tertiary center. Our results showed that the prevalence of moderate-to-severe tricuspid regurgitation in our total ECHO patient population was 2.8%. Of these, approximately 1 in 8 patients with moderate-to-severe tricuspid regurgitation would be potentially suitable for percutaneous intervention, and suggests a large, unmet clinical need in this population.