TRIGISTRY: Benefit of isolated surgical valve repair or replacement for functional tricuspid regurgitation and long-term outcomes stratified by the TRI-SCORE
Reported from ESC Congress 2024
Alex Sticchi provides his take on the TRIGISTRY study presented by Julien Dreyfus at the ESC Congress 2024 in London.
Simultaneous publication in European Heart Journal, ehae578
Why this study? The rationale/objective
Tricuspid regurgitation (TR) is a significant clinical challenge due to its high prevalence, especially in the elderly, and its association with increased mortality and morbidity. Despite guidelines recommending surgical intervention for patients with severe TR, many continue to be managed conservatively, primarily due to concerns over high postoperative mortality and uncertainty regarding the benefits of surgical correction. This study aimed to identify which patient subsets, as stratified by the TRI-SCORE, benefit most from isolated tricuspid valve (TV) repair or replacement, with a focus on long-term survival outcomes over a 10-year period.
How was it executed? The methodology
The study utilized data from TRIGISTRY, an international, multicenter registry comprising 1,768 patients with severe isolated functional TR across 33 centers in 10 countries. Of these patients, 1,217 (69%) were managed conservatively, while 551 (31%) underwent isolated TV surgery, with 200 patients (36%) undergoing valve repair and 351 patients (64%) undergoing valve replacement.
Patients were stratified by TRI-SCORE into low (≤3 points), intermediate (4-5 points), and high (≥6 points) risk categories. Baseline characteristics varied across these categories:
- Low TRI-SCORE (N=591): 33.8% of patients (200) underwent surgery, with the surgical group being significantly younger (average age 64.3 vs. 71.7 years, P < 0.0001) and more likely to be female (70% vs. 59%, P < 0.0001).
- Intermediate TRI-SCORE (N=557): 27.1% of patients (151) underwent surgery, with the surgical group being moderately younger (average age 70.8 vs. 72.5 years, P = 0.03) and having a higher proportion of females (66% vs. 53%, P < 0.0001).
- High TRI-SCORE (N=620): Surgical patients comprised 32.9% of this group (204 patients), while 67.1% (416 patients) were managed medically. There were no significant differences in age (74.1 vs. 75.3 years, P = 0.22) or gender distribution (61% vs. 59%, P = 0.39) between the surgical and medical groups.
Statistical analyses, including inverse probability of treatment weighting (IPTW), were used to adjust for baseline differences, with survival rates assessed using Kaplan-Meier survival curves.
What is the main result?
The study found no overall significant difference in 10-year survival between the surgical and conservative management groups (41% vs. 36%; HR 0.97; 95% CI 0.88-1.08, P=0.57). However, results varied significantly by TRI-SCORE category:
- Low TRI-SCORE (≤3 points): Surgery significantly improved survival compared to conservative management (72% vs. 44%; HR 0.27; 95% CI 0.20-0.37, P<0.0001). Notably, valve repair demonstrated a survival rate of 84% (HR 0.11; 95% CI 0.06-0.19, P<0.0001), while valve replacement showed a survival rate of 61% (HR 0.65; 95% CI 0.47-0.90, P=0.009).
- Intermediate TRI-SCORE (4-5 points): No significant difference in survival was observed overall (36% vs. 37%; HR 1.17; 95% CI 0.98-1.40, P=0.09). Valve repair provided a benefit with a survival rate of 59% (HR 0.49; 95% CI 0.35-0.68, P<0.0001), while valve replacement was associated with poorer outcomes, with a survival rate of 25% (HR 1.43; 95% CI 1.18-1.72, P=0.0002).
- High TRI-SCORE (≥6 points): Surgery did not improve survival compared to conservative management (20% vs. 24%; HR 1.06; 95% CI 0.91-1.25, P=0.45). Valve repair showed a survival rate of 28% (HR 0.86; 95% CI 0.68-1.08, P=0.20), and valve replacement had a significantly lower survival rate of 17% (HR 1.58; 95% CI 1.35-1.86, P<0.0001).
Critical reading and relevance for clinical practice
The study by Dreyfus et al., supported by TRIGISTRY data, presents a detailed analysis of surgical interventions for severe tricuspid regurgitation (TR) stratified by the TRI-SCORE. This study is particularly relevant in addressing two major misconceptions: first, the belief that severe TR is a benign condition, and second, the notion that surgery for TR is invariably high-risk.
TRI-SCORE as a tool for risk stratification
The TRI-SCORE effectively stratifies patients based on their risk and predicts outcomes following isolated tricuspid valve (TV) surgery. Patients with a low TRI-SCORE (≤3) showed significant benefits from surgery, with notably higher survival rates when compared to conservative management. This emphasizes the importance of early surgical intervention before the onset of significant right ventricular (RV) failure and secondary organ dysfunction. In contrast, patients with a high TRI-SCORE (≥6), who typically present with advanced disease and irreversible organ damage, did not benefit from surgical intervention. This finding aligns with conclusions in the broader literature, which highlight that advanced-stage TR often leads to poor outcomes regardless of treatment strategy due to irreversible damage from prolonged congestion and fibrosis.
The distinction between repair and replacement in intermediate TRI-SCORE patients
In the intermediate TRI-SCORE group, valve repair was associated with improved survival, whereas valve replacement was not. This distinction is crucial for guiding clinical decision-making, particularly because repair is associated with better outcomes in this group. The need to preserve native valve function and avoid the complications associated with prosthetic valves likely contributes to the observed benefits of repair over replacement in these patients.
Potential of transcatheter interventions
Given the mixed results of surgery in the intermediate and poor outcomes in the high TRI-SCORE groups, transcatheter interventions could offer a potential alternative, particularly for patients who are poor surgical candidates. These approaches could reduce procedural risks and may offer improved outcomes, especially in the intermediate-risk group. However, the benefits in high-risk patients remain uncertain and would require more evidence from future studies.
Conclusion
The findings from the TRIGISTRY initiative highlight the necessity of early intervention in patients with severe TR, particularly those with low TRI-SCOREs. In the intermediate-risk group, valve repair demonstrates clear survival benefits, while replacement may pose additional risks. These insights emphasize the importance of tailored surgical approaches and suggest that transcatheter interventions could potentially improve outcomes in higher-risk populations, though further research is needed.
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