Introduction: The Evolution of Tricuspid Intervention
The tricuspid valve, historically referred to as the forgotten valve, has moved to the forefront of structural heart intervention. Severe tricuspid regurgitation (TR) is associated with significant morbidity and mortality, yet surgical intervention remains high-risk for many patients due to comorbidities. Transcatheter therapies have emerged as a viable alternative, primarily categorized into transcatheter edge-to-edge repair (TEER) and transcatheter tricuspid valve annuloplasty (TTVA). While both aim to reduce TR, their mechanisms differ: TEER focuses on leaflet coaptation, whereas TTVA addresses annular dilatation. Identifying the right patients for these procedures is critical for procedural success and long-term outcomes. The GLIDE score, initially developed to predict success in TEER, has now been evaluated for its utility in TTVA, offering clinicians a standardized tool for preprocedural planning.
Highlighting Key Study Insights
The study provides several critical insights for the structural heart community. First, it confirms that the GLIDE score—comprising septolateral gap, predominant jet location, image quality, chordal structure density, and en-face jet morphology—is a reliable predictor of outcomes in TTVA. Second, it highlights that patients with low GLIDE scores (0-1) have an exceptionally high probability of achieving residual TR grade I or less. Third, the research introduces a modified GLIDE score that replaces chordal density with annular diameters, significantly improving predictive accuracy for annuloplasty-specific procedures.
Background: The Clinical Challenge of Tricuspid Regurgitation
Tricuspid regurgitation is often a progressive condition characterized by right ventricular remodeling and annular dilatation. As the annulus enlarges, the leaflets fail to coapt, leading to a vicious cycle of volume overload and further dilatation. While TEER has become the most common transcatheter approach, TTVA offers a more physiological repair by mimicking surgical annuloplasty rings. However, the success of TTVA is highly dependent on the anatomical suitability of the tricuspid apparatus. Until recently, there was a lack of validated scoring systems specifically tailored to predict the success of annuloplasty devices. The validation of the GLIDE score in this context represents a significant step toward precision medicine in interventional cardiology.
Study Design and Methodology
This study was a retrospective, multicenter analysis involving 204 consecutive patients who underwent TTVA between 2018 and 2023 at two tertiary German medical centers. The primary objective was to determine if the GLIDE score, which was originally designed for the TriClip or Pascal systems (TEER), could be extrapolated to annuloplasty systems.
Patient Population and Baseline Characteristics
The cohort consisted of patients with symptomatic, severe TR who were deemed at high surgical risk by a multidisciplinary heart team. Preprocedural assessment was performed using comprehensive transesophageal echocardiography (TEE). The GLIDE score was calculated based on five parameters: septolateral coaptation gap, jet location (central vs. non-central), TEE image quality, chordal density in the landing zone, and the morphology of the regurgitant jet on en-face views.
Endpoints and Success Criteria
The study defined procedural success through several metrics: achieving a residual TR grade of I or less, a residual TR grade of II or less, and a reduction in TR severity by at least two grades. These endpoints are clinically relevant as even moderate residual TR (grade II) is associated with better functional outcomes compared to severe TR.
Key Findings: The Predictive Power of GLIDE
The results of the study underscore the utility of the GLIDE score in the TTVA population. Residual TR grade ≤ I was achieved in 44.6% of the total cohort. More notably, 83.7% of patients experienced a reduction of two or more TR grades, and 72.8% achieved a residual TR of grade II or less.
The Correlation Between Score and Success
A clear inverse relationship was observed between the GLIDE score and procedural success. Patients with a score of 0 or 1 had a 79% success rate in achieving TR ≤ I. In contrast, those with a score of 4 or higher saw this success rate drop precipitously to just 19%. Statistical analysis confirmed that lower GLIDE scores were significantly associated with better outcomes across all measured parameters (P < 0.001 for residual TR ≤ I and ≤ II; P = 0.001 for TR reduction ≥ 2 grades). Even after adjusting for the baseline severity of TR, the GLIDE score remained an independent predictor of success, suggesting that anatomical complexity, rather than just disease stage, dictates procedural feasibility.
Refining the Tool: The Modified GLIDE Score
While the original GLIDE score performed well, the investigators recognized that TTVA-specific anatomical factors might further enhance its utility. Because annuloplasty focuses on the annulus rather than the leaflets and chords, the researchers evaluated a modified version of the score.
Incorporating Annular Metrics
The modified GLIDE score excluded chordal structure density—a parameter more relevant to the placement of clips—and instead included the anteroseptal and bicommissural annular diameters. This modification aligns the score more closely with the mechanical goals of annuloplasty devices.
Performance and Validation
The modified GLIDE score demonstrated superior predictive performance, with an area under the curve (AUC) of 0.84, compared to 0.79 for the original score. To ensure the robustness of these findings, the modified score was tested in an external validation cohort of 86 patients, where it maintained a strong AUC of 0.76. This suggests that while the original GLIDE score is a versatile tool, tailoring it to the specific mechanism of the device can provide even greater precision for clinical decision-making.
Expert Commentary: Clinical Implications and Limitations
The findings from this study have immediate implications for patient selection in structural heart programs. The ability to identify patients who are unlikely to benefit from TTVA (those with high GLIDE scores) allows clinicians to consider alternative therapies, such as transcatheter tricuspid valve replacement (TTVR) or palliative medical management, earlier in the clinical course.
Mechanistic Insights
The success of TTVA relies on the ability of the device to cinch the annulus and bring the leaflets closer together. A large septolateral gap or an eccentric jet indicates a degree of anatomical distortion that annuloplasty alone may not be able to overcome. The inclusion of annular diameters in the modified score captures the ‘burden’ of dilatation that the device must counteract.
Study Limitations
Despite the promising results, the study has limitations. It was retrospective in nature and focused on tertiary centers with high procedural volumes, which may limit the generalizability of the success rates to lower-volume centers. Furthermore, while the GLIDE score focuses on echocardiographic parameters, other factors such as right ventricular function and pulmonary artery pressures also play a role in long-term clinical success and were not the primary focus of this scoring system.
Conclusion: Moving Toward Anatomical Precision
The validation of the GLIDE score in TTVA represents a milestone in the standardization of tricuspid interventions. By providing a clear, evidence-based framework for assessing anatomical suitability, the GLIDE score helps bridge the gap between diagnostic imaging and procedural outcomes. The further enhancement of the score through the inclusion of annular diameters highlights the importance of matching the right tool to the right anatomical challenge. As transcatheter tricuspid therapies continue to evolve, such scoring systems will be indispensable for optimizing patient outcomes and ensuring the efficient use of healthcare resources in the management of complex heart valve disease.
References
1. Althoff J, Mehrkens D, Rudolph F, et al. GLIDE Score is associated with procedural success in patients undergoing direct transcatheter tricuspid valve annuloplasty. Eur Heart J Cardiovasc Imaging. 2025; doi:10.1093/ehjci/jeaf338.
2. Lurz P, Stephan T, Besler C, et al. Transcatheter Edge-to-Edge Repair for Tricuspid Regurgitation. JACC: Cardiovascular Interventions. 2021.
3. Hahn RT, Nabauer M, Zuber M, et al. Intraprocedural Imaging of Transcatheter Tricuspid Valve Interventions. JACC: Cardiovascular Imaging. 2019.