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.

Congestion patterns in severe tricuspid regurgitation and transcatheter treatment: Insights from a multicentre registry

AIMS

While invasively determined congestion holds mechanistic and prognostic significance in acute heart failure (HF), its role in patients with tricuspid regurgitation (TR)-related right- heart failure (HF) undergoing transcatheter tricuspid valve intervention (TTVI) is less well established. A comprehensive understanding of congestion patterns might aid in procedural planning, risk stratification, and the identification of patients who may benefit from adjunctive therapies before undergoing TTVI. The aim of this study was to investigate the role of congestion patterns in patients with severe TR and its implications for TTVI.

METHODS AND RESULTS

Within a multicentre, international TTVI registry, 813 patients underwent right heart catheterization (RHC) prior to TTVI and were followed up to 24 months. The median age was 80 (interquartile range 76-83) years and 54% were women. Both mean right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP) were associated with 2-year mortality on Cox regression analyses with Youden index-derived cut-offs of 17 mmHg and 19 mmHg, respectively (p < 0.01 for all). However, RAP emerged as an independent predictor of outcomes following multivariable adjustments. Pre-interventionally, 42% of patients were classified as euvolaemic (RAP <17 mmHg, PCWP <19 mmHg), 23% as having left-sided congestion (RAP <17 mmHg, PCWP ≥19 mmHg), 8% as right-sided congestion (RAP ≥17 mmHg, PCWP <19 mmHg), and 27% as bilateral congestion (RAP ≥17 mmHg, PCWP ≥19 mmHg). Patients with right-sided or bilateral congestion had the lowest procedural success rates and shortest survival times. Congestion patterns allowed for discerning specific patient's physiology and specifying prognostic implications of right ventricular to pulmonary artery coupling surrogates.

CONCLUSION

In this large cohort of invasively characterized patients undergoing TTVI, congestion patterns involving right-sided congestion were associated with low procedural success and higher mortality rates after TTVI. Whether pre-interventional reduction of right-sided congestion can improve outcomes after TTVI should be established in dedicated studies.

An Animal Model of Functional Tricuspid Regurgitation by Leaflet Tethering Using Image-Guided Chordal Encircling Snares

Several interventional therapies are in development to treat functional tricuspid regurgitation. Most have failed to achieve adequate efficacy, as animal models of this lesion are lacking. We developed a new image-guided technique in swine, by tethering the tricuspid valve chordae using echo-guided chordal encircling snares. Five swine underwent baseline echocardiographic assessment of tricuspid valve function, followed by echo-guided placement of snares that encircle the chordae inserting into the anterior and posterior tricuspid valve leaflets. Tethering these snares and stabilizing them on the right ventricle caused the regurgitant fraction to increase from 8.48±5.38% to 48.76±12.5%, and the valve tenting area to increase from 60.26±52.19 to 160.9±86.92 mm2. Image-guided chordal encircling snares could reproducibly induce clinically significant levels of functional tricuspid regurgitation and create a valve geometry like that seen in patients, providing a new animal model for use to study novel interventional devices.

Multimodality Imaging Approach for Planning and Guiding Direct Transcatheter Tricuspid Valve Annuloplasty

Interest in transcatheter treatment of tricuspid regurgitation (TR) has grown significantly in recent years due to increasing evidence correlating TR severity with mortality and to limited availability of surgical options often considered high-risk in these patients. Although edge-to-edge repair is currently the main transcatheter therapeutic strategy, tricuspid valve direct annuloplasty can also be performed safely and effectively to reduce TR and improve heart failure symptoms and quality of life. In the annuloplasty procedure, an adjustable band is implanted around the tricuspid annulus to reduce valvular size and improve TR. Patient selection and careful preoperative imaging, including transthoracic echocardiography, transesophageal echocardiography, and computed tomography, are critical for procedural success and proper device implantation. Compared to edge-to-edge repair, perioperative imaging with transesophageal echocardiography and fluoroscopy is particularly challenging. Alignment and insertion of the anchors are demanding but essential to achieve good results and avoid damaging the surrounding structures. The presence of shadowing artifacts due to cardiac devices makes the acquisition of good-quality images even more challenging. In this review, we discuss the current role of multimodality imaging in planning direct transcatheter tricuspid valve annuloplasty and describe all procedural steps focusing on echocardiographic monitoring.

Implications of tricuspid regurgitation and right ventricular volume overload in patients with heart failure with preserved ejection fraction

AIMS

The aim of this study was to assess the pathophysiological implications of severe tricuspid regurgitation (TR) in patients with heart failure with preserved ejection fraction (HFpEF) by using tricuspid transcatheter edge-to-edge repair (T-TEER) as a model of right ventricular (RV) volume overload relief.

METHODS AND RESULTS

This prospective interventional single arm trial (NCT04782908) included patients with invasively diagnosed HFpEF. The following parameters were prospectively assessed before and after T-TEER: left ventricular (LV) diastolic properties by invasive pressure-volume loop recordings; biventricular time-volume curves and function as well as septal curvature by cardiac magnetic resonance imaging; strain analyses for timing of septal motion. Overall, 20 patients (median age 78, interquartile range [IQR] 72-83 years, 65% female) were included. T-TEER reduced TR by a median of 2 (of 5) grades (IQR 2-1). T-TEER increased LV stroke volume and LV end-diastolic volume (LVEDV) (p < 0.001), without increasing LV end-diastolic pressure (LVEDP) (p = 0.094), consequently diastolic function improved with a reduction in LVEDP/LVEDV (p = 0.001) and a rightward shift of the end-diastolic pressure-volume relationship. The increase in LVEDV correlated with a decrease in RV end-diastolic volume (p < 0.001) and LV transmural pressure increased (p = 0.028). Secondary to a decrease in early RV filling, improvements in early LV filling were observed, correlating with an alleviation of leftwards bowing of the septum (p < 0.01, respectively).

CONCLUSION

Diastolic LV properties in patients with HFpEF and severe TR are importantly determined by ventricular interaction in the setting of RV volume overload. T-TEER reduces RV volume overload and improves biventricular interaction and physiology.

Changes in right ventricular function and clinical outcomes following tricuspid transcatheter edge-to-edge repair

AIMS

Prognostic impact of post-procedural changes in right ventricular (RV) function after tricuspid transcatheter edge-to-edge repair (T-TEER) is still unclear. We investigated association of RV function and its post-procedural changes with clinical outcomes in patients undergoing T-TEER.

METHODS AND RESULTS

We retrospectively analysed 204 patients who underwent T-TEER and echocardiographic follow-up at 3 months after T-TEER. RV function was assessed by RV fractional area change (RVFAC), and RV dysfunction was defined as RVFAC <35%. Patients with an increase in RVFAC from baseline to the follow-up were considered as RV responders. Patients were divided into four groups according to baseline RVFAC and the RV responder. The primary outcome was a composite of mortality and hospitalization due to heart failure within 1 year. Forty-five of 204 patients (22.1%) had RVFAC <35% at baseline, and 71 (34.8%) were RV responders. The association between the RV responder and the composite outcome had a significant interaction with RVFAC at baseline. Among patients with baseline RVFAC <35%, RV responders had a lower risk of the composite outcome than RV non-responders, while this association was not significant in those with baseline RVFAC ≥35%. Among patients with baseline RVFAC <35%, a smaller RV diameter and a greater reduction of tricuspid regurgitation were predictors for the RV responder.

CONCLUSION

Post-procedural increase in RVFAC after T-TEER is associated with improved outcomes in patients with RV dysfunction. The factors related to the increase in RVFAC may support patient selection for T-TEER in patients with RV dysfunction.

Role of preexisting right ventricular remodeling in symptoms and prognosis after transcatheter tricuspid valve repair

BACKGROUND

Severe tricuspid regurgitation (TR) is associated with chronic volume overload and right ventricular remodeling (RVR). Transcatheter tricuspid valve repair (TTVr) reduces TR and can improve quality of life (QoL), but the role of preprocedural RVR on TTVr outcomes remains unclear.

AIMS

To investigate the role of RVR on outcomes after TTVr for severe TR.

METHODS

Consecutive patients undergoing TTVr (61% edge-to-edge vs. 39% direct annuloplasty) for severe TR were retrospectively compared by preexisting RVR which was defined as dilation of RV mid-level diameter (> 35 mm) according to guidelines. QoL was evaluated using NYHA class, Minnesota Living with Heart Failure Questionnaire (MLHFQ), 36-Item Short Form Health Survey (SF-36), and 6-min walking distance (6MWD) 1-month after TTVr. Mid-term mortality and heart failure (HF) hospitalization were assessed through 1 year.

RESULTS

RVR was present in 137 of 223 patients (61%). Symptoms and QoL improved equally in both groups: ≥ 1 NYHA class (57% vs. 65% of patients with vs. without RVR, respectively), 6MWD (36% vs. 34%), MLHFQ (81% vs. 69%), and SF-36 (68% vs. 65%) improvement. One-year mortality and HF hospitalization were significantly higher in patients with RVR (24% and 30%, respectively) than in patients without (8% and 13%, both p < 0.05). In multivariable analysis, RVR was independently associated with mortality (HR 2.3, 95%CI (1.0-5.0), p = 0.04) and the combined endpoint of mortality or rehospitalization (HR 2.0, 95%CI (1.1-3.8), p = 0.03).

CONCLUSIONS

TTVr was associated with significant QoL improvement after 1 month, irrespective of RVR. Despite increased mortality and rehospitalization for heart failure, TTVr in the presence of RVR still provides substantial symptomatic benefit for patients with severe TR.

Tricuspid Valve Transcatheter Edge-To-Edge Repair Guidance with Transesophageal Echocardiography and Intracardiac Echocardiography

As transcatheter tricuspid interventions have emerged, especially edge-to-edge repair, imaging has shown to be key in optimizing transcatheter outcomes. Given the location of the tricuspid valve relative to the esophagus, transesophageal echocardiography has proven difficult and utilization of three-dimensional (3D) multiplanar reconstruction has become essential. Three-dimensional intracardiac echocardiography is a useful imaging adjunct for tricuspid edge-to-edge repair. As 3D intracardiac echocardiography evolves, it may supplant transesophageal echocardiography as the imaging modality of choice in transcatheter tricuspid valve interventions.

Comparison of outcomes between transcatheter tricuspid valve repair and surgical tricuspid valve replacement or repair in patients with tricuspid insufficiency

BACKGROUND

Tricuspid regurgitation is associated with significant morbidity and mortality, but with limited treatment options. The objective of this study is to compare the demographic characteristics, complications, and outcomes of transcatheter tricuspid valve repair (TTVr) versus surgical tricuspid valve replacement (STVR) or surgical tricuspid valve repair (STVr), using real-world data from the National Inpatient Sample (NIS) database.

METHODS AND RESULTS

Our study analyzed data from the National Inpatient Sample (NIS) database from 2016 to 2018 and identified 92, 86, and 84 patients with tricuspid insufficiency who underwent STVr, STVR, and TTVr, respectively. The mean ages of patients who received STVr, STVR, and TTVr were 65.03 years, 66.3 years, and 71.09 years, respectively, with TTVr patients significantly older than those who received STVr (P < 0.05). Patients who received STVr or STVR had higher mortality rates (8.7% and 3.5%, respectively) compared to those who received TTVr (1.2%). Patients who underwent STVr or STVR were also more likely to experience perioperative complications, including third-degree atrioventricular block (8.7% STVr vs. 1.2% TTVr, P = 0.329; 38.4% STVR vs. 1.2% TTVr, P < 0.05), respiratory failure (5.4% STVr vs. 1.2% TTVr, P = 0.369; 15.1% STVR vs. 1.2% TTVr, P < 0.05), respiratory complications (6.5% STVr vs. 1.2% TTVr, P = 0.372; 19.8% STVR vs. 1.2% TTVr, P < 0.05), acute kidney injury (40.2% STVr vs. 27.4% TTVr, P = 0.367; 34.9% STVR vs. 27.4% TTVr, P = 0.617), and fluid and electrolyte disorders (44.6% STVr vs. 22.6% TTVr, P = 0.1332; 50% STVR vs. 22.6% TTVr, P < 0.05). In addition, the average cost of care and the average length of hospital stay were higher for patients who underwent STVr or STVR than for those who received TTVr (USD$37995 ± 356008.523 STVr vs. USD$198397 ± 188943.082 TTVr, P < 0.05; USD$470948 ± 614177.568 STVR vs. USD$198397 ± 188943.082 TTVr, P < 0.05; 15.4 ± 15.19 STVr vs. 9.6 ± 10.21 days TTVr, P = 0.267; 24.7 ± 28.81 STVR vs. 9.6 ± 10.21 days TTVr, P < 0.05).

CONCLUSION

TTVr has shown to have favorable outcomes compared to STVr or STVR, but more research and clinical trials are required to help formulate evidence-based guidelines for the role of catheter-based management in tricuspid valve disease.

Initial experience with transcatheter tricuspid valve repair in patients with cardiac amyloidosis

AIMS

Wildtype transthyretin amyloid cardiomyopathy is an under-recognized cause of heart failure in elderly patients. Transcatheter tricuspid valve repair is a newly emerging therapeutic option for severe tricuspid regurgitation (TR). We present first insights into safety and possible benefits of this procedure in patients with cardiac amyloidosis.

METHODS AND RESULTS

Eight patients with cardiac non-hereditary (wildtype) transthyretin (ATTRwt) amyloidosis and severe to torrential TR, undergoing successful transcatheter tricuspid valve repair, were included in the analysis and compared to a control group of 21 patients without cardiac amyloidosis. All patients presented with an advanced stage of amyloid cardiomyopathy. Primary endpoint was reduction in TR at 3 months follow-up. Secondary endpoints were feasibility, safety, hospitalization or death, clinical improvement, cardiac biomarkers, and structural and functional right heart parameter obtained by echocardiography. Transcatheter tricuspid valve repair resulted in a significant reduction of TR (IV to II, P = 0.008) in all eight patients with cardiac amyloidosis (100%). Device success (amyloidosis 75% vs. control group 86%, P = 0.597) and overall probability of hospitalization or death (amyloidosis 13% vs. control group 25%, P = 0.646) were similar compared with those in the control group at 3 months follow-up. Transcatheter tricuspid valve repair led to an improvement of New York Heart Association functional class (P = 0.031) and 6 min walking distance (from 313 ± 118 to 337 ± 106, P = 0.012). TR reduction in amyloidosis patients was less extensive compared with that in control group (TR-reduction 1.6 ± 0.3, P = 0.008 vs. control group 2.3 ± 0.3, P < 0.0001). Furthermore, these patients showed no significant improvement of structural right heart parameters.

CONCLUSIONS

Transcatheter tricuspid valve repair is a safe and feasible new treatment option in patients with amyloid cardiomyopathy and has the potential to improve TR-grade and clinical status. However, the benefit appears to be less pronounced compared with patients without cardiac amyloidosis.

The TriClip system for edge-to-edge transcatheter tricuspid valve repair. A Spanish multicenter study

INTRODUCTION AND OBJECTIVES

In patients with tricuspid regurgitation (TR), edge-to-edge transcatheter tricuspid valve repair (TTVR) is the strategy with the highest penetration worldwide. A dedicated edge-to-edge TTVR system has recently become available in Europe. The present study describes the initial experience with the system in Spain.

METHODS

This multicenter study collected individual data from the centers accepted for the use of the novel system within an initial limited release. Between June 2020 and March 2021, all patients undergoing an edge-to-edge TTVR using the TriClip system in Spain were included in the study. The primary endpoint was the achievement of a TR reduction of at least 1 grade at discharge.

RESULTS

We included 34 patients. Most of them reported a previous history of atrial fibrillation (91%) and only 1 had a pacemaker lead. The primary endpoint (TR reduction of at least 1 grade at discharge) was met in all patients. Most of the patients required 1 (47%) or 2 clips (44%) with a clear predominance of XT (87%) over NT (13%). The location of the first clip was anteroseptal in >90% of the patients. Only 1 patient had a partial detachment, which was stabilized with additional clips in the same procedure. At discharge, TR severity was≤2 in 91% of patients. At 3 months, mortality was nil. Overall, 88% of patients were in New York Heart Association functional class≤2 and 80% had residual TR≤2.

CONCLUSIONS

Edge-to-edge TTVR seemed to be effective and safe with a sustained TR reduction at 3 months. Further studies will be needed to confirm our findings.

Tricuspid Valve Percutaneous Therapies

PURPOSE OF REVIEW

In this review, we have focused on the currently available transcatheter tricuspid valve therapies, device selection, as well as role and management of tricuspid regurgitation (TR) in the setting of other transcatheter valvular procedures.

RECENT FINDINGS

In this review, we have enlisted the recently finished as well as ongoing trials in the percutaneous tricuspid valve therapies. TR is highly prevalent yet remains underrecognized and is often untreated. TR has traditionally been managed conservatively with medical therapies including diuretics for volume management, whereas surgical therapies are reserved for those undergoing left-sided valvular surgery. Although the transcatheter devices for tricuspid repair and replacement are in clinical trials, the experience to date for their effectiveness and safety has been reassuring.

Transcatheter interventions for valvular heart diseases in liver cirrhosis patients

There is an increasing prevalence of patients who have both liver cirrhosis (LC) and severe valvular heart disease. This combination typically poses prohibitive risk for liver transplantation. LC related malnourishment, hypoalbuminemia and hyperdynamic circulation places patients with severe LC at higher rates for significant bleeding and/or thrombosis, as well as infectious and renal complications, after either surgical or transcatheter valvular interventions. Although there remains scarce comparative evidence, the preponderance of data suggest that percutaneous strategies are preferred over surgical ones. A multidisciplinary team is ideal for identifying those patients with LC who would benefit from transcatheter valvular heart interventions.

Etiology, epidemiology, pathophysiology and management of tricuspid regurgitation: an overview

Significant tricuspid regurgitation (TR) is a common finding, affecting about one in twenty-five subjects among the elderly and presenting more frequently in women than in men. This review summarizes data concerning etiology, epidemiology, pathophysiology and management strategies of TR. The tricuspid valve (TV) has a broad anatomical variability. Classically, TR has been distinguished as primary and secondary or functional TR (FTR), with the latter being the most prevalent. FTR is a multifactorial disorder, resulting from maladaptive right ventricular remodeling secondary to pulmonary hypertension or from atrial fibrillation leading to dilation of the right atrium, tricuspid annulus and base of the right ventricle, with pathological TV coaptation. Thus two main types of FTR can be identified: pulmonary hypertension-FTR and idiopathic-FTR, depending on which factor, ventricular or atrial respectively, is the primum movens of the disease. Appreciable evidence suggests that significant TR leads to worsening prognosis regardless of the underlying etiology and should be addressed as a separate therapeutic target. The treatment of TR in patients undergoing left-sided cardiac surgery is well established. Isolated surgical repair of TR is instead rarely performed because patients are often deemed inoperable due to prohibitive risk. Besides, perioperative mortality remains higher than for any other valve. Several transcatheter TV replacement and repair systems, the latter mostly borrowed from percutaneous treatment systems of mitral regurgitation or from TV repair surgical techniques, have shown efficacy and safety when used on the TV. These could provide an effective treatment option for patients not eligible for surgery.

Transcatheter Leaflet Strategies for Tricuspid Regurgitation TriClip and CLASP

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

The Role of Intracardiac Echocardiography in Percutaneous Tricuspid Intervention: A New ICE Age

The prevalence of severe tricuspid regurgitation in older patients is high, and the clinical relevance is perceived more and more in recent years. Many of these patients are not suitable for surgery because of their age and comorbidities. Therefore, a variety of percutaneous interventions have been developed to address this unmet need. Procedural success strongly depends on adequate imaging during the intervention. Although transesophageal echocardiography is the standard of care, imaging may be limited due to anatomic factors and adverse acoustic shadowing. In this review, we discuss the current and future role of intracardiac echocardiography in tricuspid valve interventions.

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.

Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Mitral and Tricuspid Valves Percutaneous Repair in Patients with Advanced Heart Failure: Panacea, or Pandora's Box?

In heart failure with reduced ejection fraction, the interventional landscape has recently expanded. New transcatheter approaches are emerging for both mitral and tricuspid secondary (functional) regurgitation. Transcatheter therapies for mitral and tricuspid valve require a more tailored approach than for the aortic valve, because of more heterogeneous clinical scenarios, anatomic features, and mechanisms of valvular lesions.

Diagnosis and Management of Failed Surgical Tricuspid Valve Annuloplasty

PURPOSE OF THE REVIEW

Annular-based strategies for treating tricuspid valve (TV) regurgitation do not always have satisfactory long-term outcomes. Management of failed TV annuloplasty can be challenging and requires a dedicated heart team approach. This review explores the treatment options available for failed TV annuloplasty.

RECENT FINDINGS

Recent developments and novel percutaneous treatment options have emerged as promising alternatives for patients with failed TV annuloplasty. Leaflet-based interventions, valve-in-valve procedures, transcatheter tricuspid valves and new-generation trans-caval valves are all feasible options, which can assure good results whilst minimizing risks for the patient. Failure of tricuspid annuloplasty is not uncommon amongst patients treated with either a tricuspid ring or suture-based device. The complex anatomy, physiology and clinical risk profile should be carefully evaluated on an individual patient-by-patient basis in order to select the most appropriate clinical and percutaneous treatment strategy. Different transcatheter tricuspid valve repair or replacement techniques may provide an attractive alternative treatment option for managing this challenging patient cohort.

Cardiac output states in patients with severe functional tricuspid regurgitation: impact on treatment success and prognosis

AIMS

To investigate whether there is evidence for distinct cardiac output (CO) based phenotypes in patients with chronic right heart failure associated with severe tricuspid regurgitation (TR) and to characterize their impact on TR treatment and outcome.

METHODS AND RESULTS

A total of 132 patients underwent isolated transcatheter tricuspid valve repair (TTVR) for functional TR at two centres. Patients were clustered according to k-means clustering into low [cardiac index (CI) < 1.7 L/min/m² ], intermediate (CI 1.7-2.6 L/min/m² ) and high CO (CI > 2.6 L/min/m² ) clusters. All-cause mortality and clinical characteristics during follow-up were compared among different CO clusters. Mortality rates were highest for patients in a low (24%) and high CO state (42%, log-rank P < 0.001). High CO state patients were characterized by larger inferior vena cava diameters (P = 0.003), reduced liver function, higher incidence of ascites (P = 0.006) and markedly reduced systemic vascular resistance (P < 0.001) as compared to TTVR patients in other CO states. Despite comparable procedural success rates, the extent of changes in right atrial pressures (P = 0.01) and right ventricular dimensions (P < 0.001) per decrease in regurgitant volume following TTVR was less pronounced in high CO state patients as compared to other CO states. Successful TTVR was associated with the smallest prognostic benefit among low and high CO state patients.

CONCLUSIONS

Patients with chronic right heart failure and severe TR display distinct CO states. The high CO state is characterized by advanced congestive hepatopathy, a substantial decrease in peripheral vascular tone, a lack of response of central venous pressures to TR reduction, and worse prognosis. These data are relevant to the pathophysiological understanding and management of this important clinical syndrome.

Comparison of transcatheter tricuspid valve repair using the MitraClip NTR and XTR systems

BACKGROUND

Transcatheter tricuspid leaflet repair (TTVr) using the MitraClip is a promising option for patients with severe tricuspid regurgitation (TR) and heart failure. However, no comparative studies of the NTR and XTR systems have been reported.

OBJECTIVES

The aim of this study was to assess the relative efficacy, safety, and clinical outcomes of patients with severe TR treated with the MitraClip NTR and XTR systems.

METHODS

Forty consecutive patients with severe TR underwent TTVr. The primary outcome was procedural success, with NYHA functional class, TR grade and major adverse cardiac and cerebrovascular events (MACCE) assessed at 30-day follow-up.

RESULTS

The majority of patients had functional TR and a greater proportion of XTR patients had torrential TR with larger coaptation gaps. Procedural success was achieved in 70% vs 80% in the NTR and XTR cohorts. Single leaflet device attachment was equal in both groups (5%). At 30-day follow-up, 70% vs 85% of NTR and XTR patients were in NYHA Class I/II. The mean reduction in TR grade was greater in the XTR group (1.5 ± 0.3 vs 2.3 ± 0.4, p-0.012). In patients with torrential TR at baseline, 55% in the XTR group achieved TR ≤ 2+ compared to none in the NTR group (p < 0.001).

CONCLUSIONS

In this first study comparing the MitraClip NTR and XTR systems for TTVr, we found both to be safe and effective, while the XTR system allowed treatment of larger coaptation gaps, greater mean reduction in TR grade, with more effective reduction of torrential TR.

Mechanical and Structural Evaluation of Tricuspid Bicuspidization in a Porcine Model

INTRODUCTION

Tricuspid regurgitation (TR) affects approximately 1.6 million Americans and is associated with just a 63.9% 1-year survival rate in its moderate to severe forms due to its asymptomatic nature and late diagnosis and surgical referral. As a result, industrial fervor has begun to broach this topic, with several percutaneous treatment devices currently under development. As much remains unknown about the tricuspid apparatus, the mechanics of these procedures remain unquantified. In this study, a testing apparatus and technique for the evaluation of percutaneous tricuspid valve (TV) bicuspidization were developed for the evaluation of these parameters in twelve porcine hearts.

METHODS

The passive relaxed myocardial state and the active contracted state were each induced in six porcine hearts and the bicuspidization experiment was run twice, the second time after induction of TR. TV annular area, cinching force, static leakage through the TV annulus, and annular ellipticity were quantified and compared among the groups.

RESULTS

The use of phenol was effective to induce functional TR by increased annular area. Cinching force was not found to differ between any of the testing states, but the bicuspidization experiment was able to reduce the TR annular area to that of its healthy counterpart in addition to reducing static leakage through the TV annulus. Despite appropriately reducing the area, bicuspidization was found to induce a more circular TV annular shape.

CONCLUSION

Taken together, these results provide a first mechanical analysis of the TV bicuspidization mechanism and may serve as a point of reference for future clinical animal studies.

[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.

Role of Echocardiography in Transcatheter Valvular Heart Disease Interventions

PURPOSE OF REVIEW

Transcatheter valvular interventions have increased in importance and utility for surgical valve repair and replacement. Cardiac imaging is the most crucial aspect of procedural planning and guidance. Echocardiography is a widely used, portable, and dynamic imaging modality used for many of these interventions. This review will summarize the role echocardiography in structural heart valvular interventions.

RECENT FINDINGS

Intraprocedural echocardiographic guidance has been a mainstay of structural heart interventions. Over the years, the use of 3-dimensional echocardiography has increased, and studies have shown utility in paravalvular leak prediction in the setting of transcatheter aortic valve replacement, procedural guidance in MitraClip repair, and in mitral and tricuspid valve therapies. Intraprocedural echocardiography is of paramount important for procedural success during all structural heart valvular interventions. Continued use of 2 and 3-dimensional echocardiography will be a major factor in driving the innovative field of structural heart interventions forward.

Current transcatheter devices to treat functional tricuspid regurgitation with discussion of issues relevant to clinical trial design

Functional or secondary tricuspid regurgitation (TR) has seen increased attention in recent times as relationships with clinically-relevant outcomes have come to light. Despite the association of increased mortality with significant TR, the disease remains under-recognized and thus relatively untreated. In addition, the disease itself has not been extensively studied and the interactions between annular dilatation, right heart disease and pulmonary hypertension are poorly understood. However, the high mortality and recurrence rate with current surgical replacement or repair techniques is well recognised, opening the door to transcatheter therapies for functional TR. The current perspective reviews the rationale for transcatheter solutions, describes some of the current approaches and discusses the ongoing questions of a poorly-studied condition which may limit the design of clinical trials for this disease.