Comparative Outcomes of Tricuspid-Dedicated Versus Non-Dedicated Devices in Transcatheter Tricuspid Edge-to-Edge Repair

Introduction

Tricuspid regurgitation (TR) is one of the most common acquired valvular heart diseases in the general population. Its presence is frequently associated with advanced symptoms of heart failure, often resulting in a marked deterioration in quality of life [1]. Due to the high risk of perioperative complications and the associated significant mortality, surgical repair of TR is performed in only a small percentage of patients with this condition. Consequently, most individuals with TR have traditionally been managed conservatively with pharmacological therapy aimed at symptom control, most commonly involving high-dose diuretics [2].

In recent years, there has been a rapid evolution in transcatheter treatment options for TR, offering a potentially safer alternative to surgical repair while effectively alleviating symptoms. Among these, transcatheter tricuspid edge-to-edge repair (T-TEER) has emerged as the most widely used interventional approach in contemporary clinical practice. This method, which involves mechanical approximation of the valve leaflets to improve their coaptation, was adapted from similar procedures performed on the mitral valve [3].

In the early phase of transcatheter tricuspid interventions, the absence of dedicated devices necessitated the off-label use of systems originally designed for mitral valve repair [4]. The subsequent introduction of purpose-built devices tailored specifically for the tricuspid anatomy has enabled refinements in procedural techniques and expanded the therapeutic potential of T-TEER [5].

The aim of this study was to compare the procedural efficacy and short-term outcomes of T-TEER performed with a non-dedicated device (MitraClip, Abbott, Santa Clara, CA, USA) versus dedicated tricuspid systems (TriClip, Abbott, Santa Clara, CA, USA, or PASCAL, Edwards Lifesciences, Irvine, CA, USA).

Material and Methods

STUDY DESIGN AND POPULATION:

This was a single-center retrospective cohort study. Based on the hospital database, we reviewed all patients who underwent transcatheter edge-to-edge repair (TEER) for mitral or tricuspid regurgitation between February 2018 and June 2024, identifying a total of 218 patients treated with this method.

In this cohort, we identified 23 patients who underwent T-TEER in our institution using a non-dedicated device (MitraClip). From this population, we excluded 1 patient with incomplete procedural data.

Subsequently, we selected an equal-sized group of 22 consecutive patients who underwent T-TEER using a dedicated device (TriClip or PASCAL) starting from the first patient treated with this method in our center.

All procedures were performed as part of an ongoing observational study conducted in accordance with the Declaration of Helsinki and approved by the local ethics committee of the Medical University of Warsaw. All patients provided written informed consent to participate in the observational study.

OUTCOMES AND DEFINITIONS:

The primary outcome was procedural technical success defined as device implantation on tricuspid valve leaflets confirmed by transthoracic or transesophageal echocardiography during the procedure. Secondary outcomes were: (1) a percentage of patients with TR grade moderate or less in transthoracic echocardiography (TTE) after the procedure, (2) a percentage of patients with TR grade moderate or less in TTE after the procedure and a TR grade reduction of at least 2 grades, and (3) mortality rates at 6 months and 1 year. We reported periprocedural complications defined as any adverse event related to the procedure that was identified in the 24 hours after the procedure. The definitions in this study were based on Mitral Valve Academic Research Consortium (MVARC) and Tricuspid Valve Academic Research Consortium (TVARC) recommendations [6,7].

Baseline patient characteristics were obtained: comorbidities, past medical history, baseline laboratory tests, and pharmacotherapy. The results of TTE from before and after the procedure were collected for each patient.

The data on comorbidities were obtained based on patient anamnesis and previous medical documentation. Atrial fibrillation (AF) was classified into first-diagnosed, paroxysmal, persistent, and permanent AF. Coronary artery disease was defined as a past myocardial infarction (MI), past revascularization with coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI), or documented stenosis of more than 50% in coronary angiography.

ECHOCARDIOGRAPHIC ASSESSMENT:

Basic echocardiographic measurements and more advanced parameters of valvular disease were collected from reports prepared by certified echocardiographers with experience in valvular heart disease. We collected available data concerning aortic, mitral, tricuspid, and pulmonic valve pathologies with a focus on mitral and tricuspid valve regurgitation assessment. Mitral and tricuspid regurgitation were assessed using qualitative, semiquantitative, and quantitative methods. MR was graded using a 3-grade classification based on the MR effective regurgitant orifice area (MR EROA), MR regurgitant volume (MRVol), and vena contracta width (MR VCW). TR was graded using a 5-grade classification based on TR effective regurgitant orifice area (TR EROA), TR regurgitant volume (TRVol), and TR vena contracta width (VCW) using the following cutoff values. Moderate TR is defined as EROA 20–39 mm2 or TRVol 30–44 ml and VCW 3–6.9 mm. Severe TR is defined as EROA 40–59 mm2 or TRvol 45–59 ml or VCW 7–13.9 mm. Massive TR is defined as EROA 60–79 mm2 or TRvol 60–74 ml or VCW 14–20.9 mm, and torrential TR is defined as EROA 80 mm2 or TRvol 75 ml or VCW 21 mm (Figure 1).

STATISTICAL ANALYSIS:

Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 29.0 (IBM Corp., Armonk, NY, USA). The Shapiro-Wilk test was performed to assess distribution of the continuous variables. Normally distributed variables are presented as mean and standard deviation (SD) and compared with the t test. The non-normally distributed variables are presented as median with interquartile range (IQR) and compared with the Mann-Whitney test. Categorical variables are presented as a number and percentage and compared using the χ² test or the Fisher exact test. Statistical significance was established at 2-sided P value below 0.05.

Results

BASELINE CHARACTERISTICS:

We analyzed data from 44 patients treated for TR with TEER. There were 22 (50.0%) patients who underwent T-TEER with the use of non-dedicated device (MitraClip), and 22 (50.0%) treated with a dedicated device (TriClip or PASCAL). Overall, there were 26 females (59.1%). The mean (SD) age was 74.7 (7.5) years in the overall cohort and there were no significant differences in age between the groups: 73.4 (8.8) years in the mitral-dedicated-device group and 76.0 (5.9) years in tricuspid-dedicated-device group (P=0.26).

The prevalence of comorbidities was high in the overall cohort, with the most common being AF, chronic kidney disease, and hypertension: 42 (95.5%), 36 (81.8%), and 35 (79.5%) patients, respectively. Moreover, AF was permanent in 32 (72.7%) patients. There were no significant differences between the groups in terms of comorbidities. Right-ventricular lead was present in 23 (52.3%) patients and there were no significant differences between the cohorts.

Baseline laboratory tests results were mostly similar between both groups, with significant differences only in serum bilirubin concentration (higher in the non-dedicated device group) and serum NT-proBNP concentration (higher in the non-dedicated device group).

All patients received intensive pharmacological treatment. The use of diuretics was high in both groups: overall, 25 (56.8%) patients received furosemide, 31 (70.5%) received torsemide, 6 (13.6%) received hydrochlorothiazide, 7 (15.9%) received spironolactone, and 20 (45.5%) received eplerenone. The 2 groups were well-balanced in terms of diuretic therapy. Overall, a high percentage of patients also received beta-blockers, angiotensin-converting enzyme inhibitors, and oral anticoagulation: 42 (95.5%), 22 (50.0%), and 38 (86.4%) patients, respectively. Most of these patients received non-vitamin K antagonist oral anticoagulants (NOAC) and only 12 patients (27.3%) received vitamin K antagonists (VKA). The main difference in pharmacotherapy between the groups was the use of SGLT-2 inhibitors, which were more commonly used in a dedicated device group compared to the non-dedicated device group: 12 patients (54.5%) compared to 4 (18.2%) patients, respectively (P=0.02). All above baseline characteristics are presented in detail in Table 1.

There were no significant differences in echocardiographic parameters between the groups apart from left-ventricular diameter in diastole (LVDd), which was higher in the non-dedicated device group (5.9 [1.1] cm compared to 4.6 [1.3] cm; P=0.006) and left-ventricular ejection fraction (LVEF), which was significantly lower in the non-dedicated device group (33.5 [24.0]% compared to 58.0 [16.0]%; P=0.009). Detailed echocardiographic characterization of included patients is presented in Table 2. The relatively small sample size and baseline imbalances reflect the retrospective nature of the study and may influence the interpretation of outcomes.

PROCEDURAL OUTCOMES:

All patients underwent T-TEER, performed either in addition to mitral transcatheter edge-to-edge repair (M-TEER) or as an isolated procedure. All patients in the non-dedicated device group underwent single-procedure concomitant mitral and tricuspid repair (MT-TEER). Most patients treated with a dedicated device underwent an isolated T-TEER procedure, with only 5 patients (22.7%) in this group having previously undergone M-TEER.

Technical success (primary outcome) was achieved in a significantly higher proportion of patients in the dedicated device group compared to non-dedicated device group: 22 (100%) and 17 (77.3%,) respectively (risk ratio 1.29; 95% CI 1.03–1.63; P=0.048). TR reduction to moderate or less was achieved in a similar percentage of patients in both groups: 16 (72.7%) patients in the non-dedicated device group and 18 (81.8%) patients in the dedicated device group (risk ratio 1.13, 95% CI 0.82–1.55; P=0.47). However, periprocedural TR grade reduction was significantly greater in the dedicated device group than the non-dedicated device group. The percentage of patients with TR grade moderate or less in TTE after the procedure and a TR grade reduction of at least 2 grades was significantly higher in a dedicated device group: 15 (68.2%) patients compared to 7 (31.8%) patients in the non-dedicated device group (risk ratio 2.14, 95% CI 1.09–4.21; P=0.02). Figures 2 and 3 provide a graphical representation of TR grade in both cohorts before and after the procedure.

Periprocedural complications occurred in 4 (9.1%) patients. There were 2 cases of single-leaflet device attachment, with 1 in each group, and there was 1 case of hemoptysis and 1 case of periprocedural transient ischemic attack (TIA), both in the non-dedicated device group. There were no statistically significant differences in the number of complications. Detailed procedural data are provided in Tables 3 and 4.

FOLLOW-UP:

The follow-up data at 6 months was available for 43 (97.7%) patients. One patient in the dedicated device group had not reached 6 months of follow-up at the time of data collection. During the first 6 months of observation, there were 2 deaths in the non-dedicated device group and no deaths in the dedicated device group. The difference in 6-month mortality was not significant.

Discussion

LIMITATIONS:

This study has several limitations. Primarily, it was a retrospective analysis of a historical patient cohort in which allocation to the dedicated or non-dedicated device group was determined by device availability at the time, rather than by blinded randomization. This introduced the potential for selection bias that could confound the results. Furthermore, as dedicated devices were introduced later, the observed improvements in procedural outcomes may partly reflect a learning-curve effect, with better results stemming from experience gained during earlier procedures using non-dedicated devices.

As this was an observational study, all eligible patients treated within the predefined study period were included rather than a pre-determined sample size; therefore, no formal power calculation was performed. Only 1 patient had missing data, who was excluded from the analysis, making it unlikely that missing data affected the study results. No statistical adjustment for potential confounders was performed due to the design and exploratory nature of the study.

Although these factors are limitations, they also reflect the real-world, observational nature of the study, capturing outcomes in an unselected patient population treated in routine clinical practice.

Conclusions

Systems dedicated to tricuspid interventions (TriClip or PASCAL) were associated with higher procedural success rates and more effective TR reduction compared with the non-dedicated device (MitraClip). Their use improved early outcomes and enabled the application of T-TEER in a broader population of patients with less-advanced heart failure. Given the limited sample size and retrospective design, the findings of this study should be interpreted with caution and regarded as exploratory and hypothesis-generating.