Idiopathic ventricular arrhythmia originating from the vicinity of lateral tricuspid annulus: The precise origin and anatomic concerns

BACKGROUND

Although the electrocardiographic and electrophysiological properties of ventricular arrhythmias (VAs) from the vicinity of the lateral tricuspid annulus (TA) have been reported in previous studies, their precise site of origin have not been addressed.

OBJECTIVE

The purpose of this study was to describe the precise origin of lateral TA-VA and the relevant anatomy.

METHODS

Consecutive patients with idiopathic lateral TA-VAs were reviewed and analyzed. Three-dimensional mapping system combined with intracardiac echocardiography (ICE) was used for anatomic reconstruction, mapping, and ablation.

RESULTS

During the study period, 63 patients with lateral TA-VAs were included. Under ICE view, a prominent enfoldment structure was observed under the valve along the lateral TA. The muscular bundle was documented in all patients (100%) within the subvalvular enfoldment with an average number and diameter of 4 ± 2 and 4.10 ± 0.73 mm, respectively. Initial ablation was attempted via the anterograde approach in 15 patients but succeeded in none. To reach the ventricular side of the TA, the catheter needed to enter the ventricular chamber and retroflexed toward the atrial side with a reverse curve. The earliest activation site was found at the valvular end of muscular bundles in 51 of the 63 patients (80.9%) with a local activation time of -26.78 ± 4.63 ms. The VAs were eliminated after an average of 4 ± 2 seconds of ablation.

CONCLUSION

The ventricular side adjacent to the lateral TA exhibits a subvalvular enfoldment-like structure, which is rich in muscular bundles and serves as the origin of TA-VAs in most patients. To reach the origins, a reverse technique is required.

First-in-human study of the K-Clip™ transcatheter annular repair system for severe functional tricuspid regurgitation

BACKGROUND

Severe TR is associated with impaired prognosis while limited interventional options available. The purpose of this observational first-in-human experience with the K-Clip™ transcatheter tricuspid annular reconstruction system is to investigate its feasibility, safety as well as short-term clinical impact on patients with severe functional tricuspid regurgitation (TR).

METHODS

In this compassionate-use, prospective, multi-center, single-arm study, 15 patients with severe symptomatic functional TR were treated with the K-Clip™ system and followed up at 30 days after discharge. Feasibility endpoints consisted of safety (major clinical cardiovascular events (MACEs), echocardiographic, clinical and functional endpoints.

RESULTS

All the 15 patients (9 males, 72.67 ± 9.42 years of age) successfully received implants and no MACEs were reported throughout the study at 30 days. Between baseline and 30 days, echocardiography showed remarkable reduction of tricuspid annular circumference and area by 14.30% and 25.96%. Improvement of ≥ + 2 grade and ≥ +3 grade TR was presented in 9/15(60.00%) and 4/15(26.67%) respectively while 10/15(66.67%) of patients had ≤ moderate TR. Clinical evaluation indicated that 86.67% of patients were finally in NYHA functional class I or II (p<0.001) and overall Kansas City Cardiomyopathy Questionnaire score improved from 62.28 ± 18.97 to 77.90 ± 11.70 (p = 0.016).

CONCLUSION

Our first-in-human results of the transcatheter tricuspid annular reconstruction using the K-Clip™ system demonstrated initial favorable procedural success, acceptable safety and remarkable TR reduction in consistent with significant clinical improvement. Larger-scaled prospective trials with longer follow-up duration are warranted to further determine whether these promising findings could be promoted to a broader population in the long term.

Incidence and causal association of functional atrial mitral regurgitation in HFpEF

Heart failure with preserved ejection fraction (HFpEF) is as common as heart failure with reduced ejection fraction. Atrial fibrillation (AF), as well as the presence of mitral regurgitation (MR), is highly prevalent in these patients. Atrial functional MR (AFMR) is a type of functional MR characterized by severe left atrial dilatation and remodeling with normal left ventricular (LV) dimensions and function. Dilatation of the mitral annulus is considered to be the main underlying mechanism, though the leaflets and the rest of the mitral apparatus play significant role in the development of MR, mainly in patients with long standing AF. There are several echocardiographic differences between atrial and ventricular functional MR, better identified with 3D echocardiography. Significant AFMR impairs prognosis, especially of patients with HFpEF, and this is important while they represent a group of under-diagnosed and under-treated patients. Finally, because focused medical evidence-based approach is not available yet, it seems that the prevention of left atrial dilatation and early restoration of sinus rhythm (SR) is the best therapeutic option.

Clinical Impact of Computational Heart Valve Models

This paper provides a review of engineering applications and computational methods used to analyze the dynamics of heart valve closures in healthy and diseased states. Computational methods are a cost-effective tool that can be used to evaluate the flow parameters of heart valves. Valve repair and replacement have long-term stability and biocompatibility issues, highlighting the need for a more robust method for resolving valvular disease. For example, while fluid-structure interaction analyses are still scarcely utilized to study aortic valves, computational fluid dynamics is used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress, and oscillatory shear index in the thoracic aorta. It has been analyzed that computational flow dynamic analyses can be integrated with other methods to create a superior, more compatible method of understanding risk and compatibility.

Challenges and future perspectives of transcatheter tricuspid valve interventions: adopt old strategies or adapt to new opportunities?

Tricuspid regurgitation (TR) is a highly prevalent valvular heart disease and is associated with an increased risk of cardiovascular events and death at long-term follow-up. Functional TR accounts for over 90% of TR and is mainly due to annular or right ventricular dilatation. Most often, TR is observed in patients with left-sided valvular heart disease (with or without previous surgical correction) and pulmonary hypertension. Isolated TR is less frequent, though burdened by high surgical mortality. This, together with an incomplete understanding of the disease, has brought to a significant undertreatment in spite of the growing evidence of the impact of severe TR on mortality. Moreover, uncertainties about the appropriate timing for intervention and the predictors of procedural success have contributed to limit TR treatment. Transcatheter tricuspid valve replacement or repair interventions represent novel and less invasive alternatives to surgery and have shown early promising results. The purpose of this review is to provide a complete and updated overview of TR pathology with a special focus on current percutaneous treatment options, future challenges and directions.

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.

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

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

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

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

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.

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.

Pulmonary hypertension and valvular heart disease

Pulmonary hypertension (PH) is an important contributor to morbidity and mortality in patients with left-sided heart disease, including valvular heart disease. In this context, elevated left atrial pressure primarily leads to the development of post-capillary PH. Despite the fact that repair of left-sided valvular heart disease by surgical or interventional approaches will improve PH, recent studies have highlighted that PH (pre- or post-interventional) remains an important predictor of long-term outcome. Here, we review the current knowledge on PH in valvular heart disease taking into account new hemodynamic PH definitions, and the distinction between post- and pre-capillary components of PH. A specific focus is on the precise characterization of hemodynamics and cardiopulmonary interaction, and on potential strategies for the management of residual PH after mitral or aortic valve interventions. In addition, we highlight the clinical significance of tricuspid regurgitation, which may occur as a primary condition or as a consequence of PH and right heart dilatation (functional). In this context, proper patient selection for potential tricuspid valve interventions is crucial. Finally, the article highlights gaps in evidence, and points toward future perspectives.

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

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

Transcatheter mitral valve repair: review of the clinical evidence

Over the past decade, different transcatheter repair techniques have been developed to treat mitral regurgitation (MR) with less invasive approaches in order to address the unmet clinical need of untreated patients with MR. The aim of this report is to provide an overview of the currently available transcatheter mitral repair options, focusing on the evidence reported so far.

Specific Anatomic Considerations for Tricuspid Interventions

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Transcatheter mitral valve chord repair

The field of mitral valve disease diagnosis and management is rapidly evolving. New understanding of pathophysiology and improvements in the adoption of sophisticated multimodality imaging modalities have led to early diagnosis and to more complex treatment. The most common cause of mitral regurgitation (MR) in the western world is in the primary alteration of the valve, which leads to degenerative leaflet prolapse due to chordal elongation or rupture and annular dilatation. Untreated, significant MR has a negative impact prognosis, leading to reduction of survival. In the setting of degenerative MR, surgical repair currently represents the standard of care. Treatment of asymptomatic patients with severe MR in the Valve Center of Excellence, in which successful repair reaches more than 95% and surgical mortality less than 1%, symbolizes the direction for the next years. Transcatheter mitral valve repair with different devices, more recently the chordal replacement ones, is providing good outcomes and became a therapeutic option in high-risk patients with degenerative MR. In the future, more advances are expected from further development of interventional techniques, careful evaluation and better patient selection. This review will focus on long-term surgical outcomes of mitral valve repair with artificial chordae and on the emerging transcatheter chordal repair devices as therapeutic options for degenerative MR patients.

Comparative Anatomy of Mitral and Tricuspid Valve: What Can the Interventionlist Learn From the Surgeon

Transcatheter valve interventions on the mitral and tricuspid valves entail increasing complexity. Part of the knowledge that has been generated during the development of mitral devices can be transferred to the tricuspid valve (TV). However, a deeper understanding of the peculiar anatomy of the TV and of the right heart chambers, together with differences and similarities between the two valves, is fundamental. This report compares the anatomy of the mitral and tricuspid valves, and its inferences with regard to transcatheter treatments.

Condensed abstract

This report explores anatomical similarities and differences between the mitral and the tricuspid valves, and their implications with regard to transcatheter treatments.