Transcatheter Tricuspid Valve Replacement: Principles and Design

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.

National Estimates for the Percentage of All Readmissions With Demographic Features, Morbidity, Overall and Gender-Specific Mortality of Transcutaneous Versus Open Surgical Tricuspid Valve Replacement/Repair

Background

The aim of the study was to determine national estimates for the percentage of all readmissions with demographic features, length of stay (LOS), cost analysis, comorbidities, complications, overall and gender-specific mortality and complications of transcutaneous tricuspid valve replacement/repair (TTVR) vs. open surgical tricuspid valve replacement/repair (open TVR).

Methods

Data were extrapolated from the Nationwide Readmissions Database (NRD) 2015-19. Of the 75,266,750 (unweighted) cases recorded in the 2015 - 2019 dataset, 429 had one or more of the percutaneous approach codes as per the ICD-10 dataset, and 10,077 had one or more of the open approach codes.

Results

Overall, the number of cases performed each year through open TVR was higher than TTVR, but there was an increased trend towards the TTVR every passing year. TTVR was performed more in females and advanced age groups than open TVR. The LOS and cost were lower in the TTVR group than in open TVR. Patients undergoing TTVR had more underlying comorbidities like congestive heart failure, hypertension, and uncomplicated diabetes mellitus. Overall mortality was 3.49% in TTVR vs. 6.09% in open TVR. The gender-specific analysis demonstrated higher female mortality in the open TVR compared to TTVR (5.45% vs. 3.03%). Male mortality was statistically insignificant between the two groups (6.8% vs. 4.3%, P-value = 0.15). Patients with TTVR had lower rates of complications than open TVR, except for arrhythmias, which were higher in TTVR. Patients undergoing open TVR required more intracardiac support, such as intra-aortic balloon pump (IABP) and Impella, than TTVR.

Conclusion

TTVR is an emerging alternative to open TVR in patients with tricuspid valve diseases, especially tricuspid regurgitation. Despite having more underlying comorbidities, the TTVR group had lower in-hospital mortality, hospital cost, LOS, and fewer complications than open TVR.

TriClip G4: A game-changer for tricuspid valve regurgitation treatment

Tricuspid valve regurgitation, or TR, is a difficult-to-manage condition. In addition to EVOQUE, percutaneous annuloplasty, and surgical repair, the TriClip G4 system has been added to the interventional therapeutic choices for TR. Recently, the Food and Drug Administration (FDA) approved the use of the TriClip G4 device to treat patients with symptomatic, severe TR who have received optimal medication therapy but are at intermediate or higher risk of surgery. This review attempts to offer a thorough examination of the procedural features, learning curves, results of the device and compares the TriClip G4 system to other interventional therapies for TR. TriClip G4 has shown to have promising results in pivotal clinical trials, be cost-effective, and improve the quality of life of patients. Furthermore, it has its unique advantages against other conventional techniques and devices.

A tissue-silicone integrated simulator for right ventricular pulsatile circulation with severe functional tricuspid regurgitation

There is a great demand for development of a functional tricuspid regurgitation (FTR) model for accelerating development and preclinical study of tricuspid interventional repair devices. This study aimed to develop a severe FTR model by creating a tissue-silicone integrated right ventricular pulsatile circulatory simulator. The simulator incorporates the porcine tricuspid annulus, valve leaflets, chordae tendineae, papillary muscles, and right ventricular wall as one continuous piece of tissue, thereby preserving essential anatomical relationships of the tricuspid valve (TV) complex. We dilated the TV annulus with collagenolytic enzymes under applying stepwise dilation, and successfully achieved a severe FTR model with a regurgitant volume of 45 ± 9 mL/beat and a flow jet area of 15.8 ± 2.3 cm2 (n = 6). Compared to a normal model, the severe FTR model exhibited a larger annular circumference (133.1 ± 8.2 mm vs. 115.7 ± 5.5 mm; p = 0.009) and lower coaptation height (6.6 ± 1.0 mm vs. 17.7 ± 1.3 mm; p = 0.003). Following the De-Vega annular augmentation procedure to the severe FTR model, a significant reduction in regurgitant volume and flow jet area were observed. This severe FTR model may open new avenues for the development and evaluation of transcatheter TV devices.

Incidence, Risk Factors, and Outcomes Associated With Permanent Pacemaker Implantation Following Tricuspid Valve Surgery

BACKGROUND

Data regarding permanent pacemaker (PPM) implantation following tricuspid valve surgery (TVS) are limited. We sought to evaluate its incidence, risk factors, and outcomes.

METHODS AND RESULTS

Medicare beneficiaries who underwent TVS from 2013 to 2020 were identified. Patients who underwent TVS for endocarditis were excluded. The primary exposure of interest was new PPM after TVS. Outcomes included all-cause mortality and readmission with endocarditis or heart failure on follow-up. Among the 13 294 patients who underwent TVS, 2518 (18.9%) required PPM placement. Risk factors included female sex (relative risk [RR], 1.26 [95% CI, 1.17-1.36], P<0.0001), prior sternotomy (RR, 1.12 [95% CI, 1.02-1.23], P=0.02), preoperative second-degree heart block (RR, 2.20 [95% CI, 1.81-2.69], P<0.0001), right bundle-branch block (RR, 1.21 [95% CI, 1.03-1.41], P=0.019), bifascicular block (RR, 1.43 [95% CI, 1.06-1.93], P=0.02), and prior malignancy (RR, 1.23 [95% CI, 1.01-1.49], P=0.04). Tricuspid valve (TV) replacement was associated with a significantly higher risk of PPM implantation when compared with TV repair (RR, 3.20 [95% CI, 2.16-4.75], P<0.0001). After a median follow-up of 3.1 years, mortality was not different in patients who received PPM compared with patients who did not (hazard ratio [HR], 1.02 [95% CI, 0.93-1.12], P=0.7). PPM placement was not associated with a higher risk of endocarditis but was associated with a higher risk of heart failure readmission (HR, 1.28 [95% CI, 1.14-1.43], P<0.001).

CONCLUSIONS

PPM implantation frequently occurs after TVS, notably in female patients and patients undergoing TV replacement. Although mortality is not increased, it is associated with higher rates of heart failure rehospitalization.

Right ventricular remodeling and clinical outcomes following transcatheter tricuspid valve intervention

AIMS

Characterize the impact of residual tricuspid regurgitation (TR) on right ventricle (RV) remodeling and clinical outcomes after transcatheter tricuspid valve intervention.

METHODS

We performed a single-center retrospective analysis of transcatheter tricuspid valve repair (TTVr) or replacement (TTVR) patients. The primary outcomes were longitudinal tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), pulmonary artery systolic pressure (PASP), and RV dimensions (RVd). We used multivariable linear mixed models to evaluate association with replacement versus repair and degree of TR reduction with changes in these echo measures over time. Multivariable Cox regression was used to identify associations between changes in these echo measures and a composite clinical outcome of death, heart failure hospitalization, or re-do tricuspid valve intervention.

RESULTS

We included a total of 61 patients; mean age was 77.5 ± 11.7 and 62% were female. TTVR was performed in 25 (41%) and TTVr in 36 (59%). Initially, 72% (n = 44) had ≤ severe TR and 28% (n = 17) had massive or torrential TR. The median number of follow up echos was 2: time to 1st follow-up was 50 days (interquartile range [IQR]: 20, 91) and last follow-up was 147 (IQR: 90, 327). Median TR reduction was 1 (IQR: 0, 2) versus 4 (IQR: 3, 6) grades in TTVr versus TTVR (p < 0.0001). In linear mixed modeling, TTVR was associated with decline in TAPSE and PASP, and TR reduction was associated with decreased RVd. In multivariable Cox regression, greater RVd was associated with the clinical outcome (hazard ratio: 9.27, 95% confidence interval: 1.23-69.88, p = 0.03).

CONCLUSION

Greater TR reduction is achieved by TTVR versus TTVr, which is in turn associated with RV reverse remodeling. RV dimension in follow-up is associated with increased risk of a composite outcome of death, heart failure hospitalization, or re-do tricuspid valve intervention.

Outpatient tricuspid regurgitation in the community: Clinical context and outcome

BACKGROUND AND AIMS

Epidemiology of tricuspid regurgitation (TR) is poorly known and its burden in the community is challenging to define. We aimed to evaluate the prevalence of TR in a geographically defined area and its outcome, in particular overall survival and hospitalization, considering different clinical contexts.

METHODS

We retrospectively analyzed consecutive outpatients referred between 2006 and 2013 for echocardiography and clinical evaluation. Patients with at least moderate TR were included and five different clinical settings were defined: concomitant significant left-sided valvular heart disease (LVHD-TR), heart failure (HF-TR), previous open-heart valvular surgery (postop-TR), pulmonary hypertension (PHTN-TR) and isolated TR (isolated-TR). Primary endpoint was a composite outcome of all-cause mortality or first hospitalization for HF.

RESULTS

Of 6797 consecutive patients with a clinical visit and echocardiograms performed in routine practice in a geographically defined community, moderate or severe TR was found in 4.8% of patients (327) . During median follow-up of 6.1 years, TR severity was a determinant of event-free survival. Analyzed for each clinical subset, eight-year event-free survival was 87 ± 7% for postop-TR subgroup, 75 ± 7% for isolated-TR, 67 ± 6% for PHTN-TR, 58 ± 6% for LHVD -TR and 52 ± 11% for HF-TR.

CONCLUSION

Moderate or more TR is a notable finding in the community and has impact on event-free survival in all clinical settings, with the worst outcomes when associated with relevant left-sided valvular heart disease and HF.

Transcatheter Systemic AV Valve-in-Valve Implantation in a Patient With LTGA and Ebstein Anomaly

We present the first in-human transcatheter systemic atrioventricular valve-in-valve implantation in a 37-year-old patient with Ebstein anomaly, levo-transposition of the great arteries, and prior systemic valve replacement. She had severe bioprosthetic valve regurgitation and reduced systolic function. She had high surgical risk and was planned for transcatheter intervention. (Level of Difficulty: Advanced.)

Transcatheter Tricuspid Valve Replacement: A Feasible Solution to a Real-world Problem

Background and Objective

As one of the most prevalent valvular pathologies affecting millions globally, moderate-to-severe tricuspid regurgitation (TR) predisposes to increased mortality. Despite the well-established risk of adverse outcomes, an overwhelming majority of TR patients are managed conservatively due to challenges associated with timely diagnosis, clinical course of the disease, competing comorbities that carry prohibitive surgical risk, and poor surgical outcomes. These challenges highlight the importance of transcatheter tricuspid valve replacement (TTVR) which has restructured TR management in promising and innovative ways.

Methods

We start with an overview of the pathophysiology of TR considering its implications in management. We then elaborate on the current state of TR management, including its limitations, thereby highlighting the unique role of TTVR. This is followed by a review of perioperative considerations such as careful patient selection, role of multimodality imaging, the various imaging techniques that are available and their contribution towards successful TTVR. We then review the valves that are currently available and under investigation, including the latest data available on device efficacy and safety, and highlight the ongoing clinical trials.

Results and Conclusions

TTVR is evolving at an exponential pace and has made its mark in the treatment of severe symptomatic tricuspid regurgitation. The promising results sustained by currently available devices and ongoing investigation of valves under development continue to pave the path for further innovation in transcatheter interventions. However, it is important to acknowledge and appreciate the novelty of this approach, the lack of long-term data on safety, efficacy, morbidity, and mortality, and use the lessons learned from real-world experiences to provide a definitive and reproducible solution for patients with symptomatic TR.

Anatomy of the Tricuspid Valve and Pathophysiology of Tricuspid Regurgitation

Transcatheter valve interventions have seen a significant increase in the past decade. The combination of improved techniques and available tools provides less invasive options supplementing surgical therapies. The tricuspid valve (TV) apparatus is a complex structure between the right atrium and the right ventricle; it generally consists of 3 leaflets (anterior, posterior, and septal) inserted in the fibrous tricuspid annulus and connected to the papillary muscle via the chordae tendinae. This article reviews TV anatomy, the pathophysiology of tricuspid regurgitation, and multimodality imaging to study TV, as well as provides an overview of transcatheter TV intervention.

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.

A Robot Mimicking Heart Motions: An Ex-Vivo Test Approach for Cardiac Devices

Purpose

The pre-clinical testing of cardiovascular implants gains increasing attention due to the complexity of novel implants and new medical device regulations. It often relies on large animal experiments that are afflicted with ethical and methodical challenges. Thus, a method for simulating physiological heart motions is desired but lacking so far.

Methods

We developed a robotic platform that allows simulating the trajectory of any point of the heart (one at a time) in six degrees of freedom. It uses heart motion trajectories acquired from cardiac magnetic resonance imaging or accelero-meter data. The rotations of the six motors are calculated based on the input trajectory. A closed-loop controller drives the platform and a graphical user interface monitors the functioning and accuracy of the robot using encoder data.

Results

The robotic platform can mimic physiological heart motions from large animals and humans. It offers a spherical work envelope with a radius of 29 mm, maximum acceleration of 20 m/s² and maximum deflection of ±19° along all axes. The absolute mean positioning error in x-, y- and z-direction is 0.21 ±0.06, 0.31 ±0.11 and 0.17 ±0.12 mm, respectively. The absolute mean orientation error around x-, y- and z-axis (roll, pitch and yaw) is 0.24 ±0.18°, 0.23 ±0.13° and 0.18 ±0.18°, respectively.

Conclusion

The novel robotic approach allows reproducing heart motions with high accuracy and repeatability. This may benefit the device development process and allows re-using previously acquired heart motion data repeatedly, thus avoiding animal trials.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13239-021-00566-3.

State-of-the-Art Review: Anatomical and Imaging Considerations During Transcatheter Tricuspid Valve Repair Using an Annuloplasty Approach

Transcatheter techniques for the treatment of tricuspid regurgitation (TR) are being more frequently used and several new devices are in development. Since 90% of patients with TR have secondary TR, catheter based systems which reduce the dilated tricuspid annulus area are of particular interest. In order to perform an annuloplasty procedure effectively and safely, knowledge about the anatomy of the tricuspid valve apparatus and especially of the annulus in relation to the important neighboring structures such as the aortic root, the RCA, the electrical pathways and the CS is fundamental. In addition, comprehensive understanding of the device itself, the delivery system, its maneuverability and the individual procedural steps is required. Furthermore, the use of multi-modality imaging is important. For each step of the procedure the appropriate imaging modality as well as the optimal; imaging planes are crucial to provide the necessary information to best guide the individual procedural step.

The impact of advances in percutaneous catheter interventions on redo cardiac surgery

Toward the end of the twentieth century, redo cardiac surgery accounted for approximately 15-20% of total cardiac surgical volume. Major risk factors for redo cardiac surgery include young age at time of the first operation, progression of native coronary artery disease (CAD), vein graft atherosclerosis, bioprosthetic valve failure and endocarditis, and transplantation for end stage heart failure. Historically, redo coronary artery bypass grafting (CABG) alone carried a mortality risk of around 4%. Factors such as older age, female sex, comorbidities, combined procedures, hemodynamic instability, and emergency procedures contributed to even higher mortality and morbidity. These poor outcomes made it necessary to look for less invasive alternate methods of treatment. Advances in catheter-based interventions have made a major impact on redo cardiac surgeries, making it no longer the first option in a majority of cases. Percutaneous interventions for recurrence following CABG, transcutaneous aortic valve replacement (TAVR) for calcific aortic stenosis, valve in valve (VIV) implantations, device closure of paravalvular leaks (PVL), and thoracic endovascular aortic repair (TEVAR) for residual and recurrent aneurysms and mitral clip to correct mitral regurgitation (MR) in heart failure are rapidly developing or developed, obviating the need for redo cardiac surgery. Our intent is to review these advances and their impact on redo cardiac surgery.

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.

Temporal Trends in Prevalence of Tricuspid Valve Disease in Hospitalized Patients in the United States

Tricuspid valve disease (TVD), particularly tricuspid regurgitation, is a common valvular pathology that is associated with increased morbidity and mortality. The prevalence of TVD in hospitalized patients has not been well characterized. We used the National Inpatient Sample to determine the overall and age- and sex-specific prevalence and temporal trends in prevalence of TVD in hospitalized patients in the US. All-cause and heart failure (HF) hospitalizations in patients ≥50 years of age from January 2006 to September 2015 in the US were identified. Temporal trends in the prevalence of TVD were studied using Poisson regression. Of 194,184,433 all-cause and 38,083,773 HF hospitalizations in patients ≥50 years of age, 3,235,292 (1.7%) and 1,787,548 (4.7%) had a diagnosis of TVD, respectively. From 2006 to 2015, the prevalence of TVD in all hospitalizations and in HF hospitalizations increased from 1.7% to 2.0% and from 3.9% to 5.7%, respectively (p_trend <0.001 for both), particularly in those ≥85 years of age and in women. In patients with TVD, primary reasons for hospitalizations were HF (20.8%), infections (10.1%), arrhythmias (9.8%), respiratory conditions (8.4%), and coronary artery disease/acute myocardial infarction (8.2%). In-hospital mortality and length of stay in patients with TVD remained unchanged, whereas costs of hospitalization increased during the study period. In conclusion, the prevalence of TVD in all hospitalized patients and in those hospitalized with HF has increased over the past several years, particularly in those ≥85 years of age and in women. Approximately 1 in 5 hospitalizations with a diagnosis of TVD is due to HF.

Current state of transcatheter tricuspid valve repair

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

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.

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.