Tricuspid valve disease is a common condition, affecting approximately 16% of the general population with at least moderate tricuspid regurgitation (TR). Isolated moderate or severe TR has been linked to increased morbidity and mortality, particularly when associated with factors like advanced age, pulmonary hypertension (PH), or right ventricular (RV) dysfunction. Despite these complications, isolated tricuspid surgery remains rare, comprising less than 1.5% of total valve surgeries in our practice. This is partly because only a small fraction of patients with isolated TR are referred for surgical treatment, likely due to the historical perception of higher morbidity and mortality with isolated tricuspid surgery compared to other single-valve procedures. This has created uncertainty about the prognosis for patients undergoing this intervention. Numerous studies have reported perioperative mortality near 10% for isolated tricuspid surgery. For instance, analysis of the American STS registry, published months ago and commented on in a prior blog post, places it at 7.3%. Some series even describe a one-year mortality of 24%.

Current clinical guidelines are clear on this issue. American guidelines do not provide a class I indication for isolated TR, while European guidelines grant a class I indication for severe, symptomatic TR. Consequently, most patients presenting for surgery already display severe right heart failure (HF) symptoms, such as ascites, edema, or dyspnea, with obvious prognostic implications. In cases without symptoms, a class II indication is considered if there is RV dysfunction or dilation. Therefore, controversy persists around the optimal timing and appropriate surgical indications for isolated tricuspid surgery. This study we now analyze raises the critical question of whether earlier intervention, before class I surgical indications develop, could improve outcomes.

The study’s objective was to compare the characteristics and outcomes of surgery for isolated severe TR based on class I (symptomatic) indications versus earlier intervention (asymptomatic severe TR with RV dilation and/or dysfunction, thus without a class I indication). All patients undergoing isolated surgery for severe TR without other concomitant valve surgery at a single center between 2004 and 2018 were consecutively analyzed. The primary outcome was mortality. The study included 159 patients (91 women [57.2%]; 115 for class I indication, 44 for early surgery) with a mean age of 59.7 years, of whom 119 (74.8%) underwent surgical repair. The mean follow-up was 5.1 years. Overall operative mortality was 5.1% (8 patients) (7.0% for class I indication, 0.0% for early surgery; p = .107). Additionally, class I patients exhibited higher composite morbidity compared to early surgery (35.7% [n = 41] versus 18.2% [n = 8]; p = .036). Cox proportional hazards model analysis indicated that class I indication versus early surgery (hazard ratio [HR], 4.62; p = .04), age (HR, 1.03; p = .046), and diabetes (HR, 2.50; p = .024) were independently associated with higher mortality during follow-up.

In conclusion, the authors argue that patients meeting class I indications for isolated tricuspid valve surgery exhibited lower survival than those undergoing earlier surgery before reaching class I indications. Early intervention may improve outcomes in these high-risk patients.

COMMENTARY:

In this highly valuable study, Wang et al. present a retrospective investigation analyzing 159 patients who underwent isolated tricuspid valve surgery for severe TR at a single center over 14 years, attended by 17 surgeons. After an average follow-up of five years, class I patients showed higher mortality rates, especially those of advanced age and with diabetes. Surprisingly, the early surgery group exhibited significantly lower short-term mortality (0% vs. 7%) and higher long-term survival, even after adjusting for confounding factors. It is noteworthy that although the initial clinical characteristics differed, with class I patients being older, more symptomatic, and presenting higher NYHA class, these results deliver a clear message: waiting until patients develop right HF symptoms is unadvisable. The study raises a rare paradox that should prompt reconsideration of current surgical guidelines. Typically, class I recommendations are associated with greater clinical benefits, both symptomatic and survival-related, compared to class II recommendations, yet this study contradicts that assumption in the findings of Wang et al.

It is essential to recognize that TR should not be underestimated as a benign valvulopathy. Multiple studies indicate nearly 50% mortality at four years in patients with moderate or severe untreated TR, even in the absence of PH or RV dysfunction, highlighting TR as an independent negative predictor. The concept of operating on valvulopathies before reaching decompensation is intuitive and partially applied to aortic and mitral surgeries. In this study, the authors demonstrated the clear advantages of early surgery for isolated tricuspid valve disease, supporting a more proactive intervention strategy for these patients. Furthermore, they emphasize the importance of opting for repair over replacement of the tricuspid valve, which has also shown to enhance survival. Recent developments in percutaneous approaches, such as the “edge-to-edge” device, and promising results from the TRILUMINATE clinical trial (also discussed in a previous blog post) in terms of quality-of-life improvement and TR reduction in select patients open new treatment possibilities for this still poorly defined disease.

The TRI-SCORE risk scale, a recently validated tool, provides valuable information for decision-making in isolated tricuspid surgery. It identifies patients at higher surgical risk, offers clues as to which patients should not undergo surgery, and even opens the door to transcatheter therapies in certain cases. However, the truly intriguing and beneficial advancement would be a scale to predict which patients with severe TR might benefit from surgery before symptoms or structural changes develop, impacting prognosis and limiting repairability as ventricular remodeling and tethering progress.

Another critical aspect is the applicability of these findings from Cleveland Clinic and other high-volume centers to other hospitals. Although early surgery for asymptomatic patients with severe TR is reasonable, in more routine practice, it is more likely that such patients will already present symptoms when seen in specialized centers (class I indication). Often, asymptomatic patients with severe TR are either not properly diagnosed or, if they are, it may be an incidental finding. Over half of these patients present with PH, over a third with RV dysfunction, three-quarters with atrial fibrillation, and over half with other significant comorbidities when referred for surgery. Therefore, it is essential that asymptomatic patients with TR undergo thorough echocardiographic follow-up by experts to detect early RV dilation and/or dysfunction, a challenging task. Early detection would allow timely surgical referral. However, a general trend among cardiologists and surgeons is to delay surgery until symptoms become clear, typically in advanced NYHA functional stages, leading to worsened patient status at surgery and poorer prognosis.

In any case, definitive conclusions cannot be drawn solely from the results of a small group of 44 patients operated on by 17 surgeons over 14 years with notable baseline group differences. Given the rarity of this surgery, assembling larger and more detailed databases remains a challenge. Nonetheless, these results contribute valuable knowledge to the sparse literature on this topic. In my view, we now have a stronger foundation for deciding between surgical intervention or close follow-up for patients with severe TR, even in the absence of class I indications.

REFERENCE:

Wang TKM, Akyuz K, Xu B, Gillinov AM, Pettersson GB, et al. Early surgery is associated with improved long-term survival compared to class I indication for isolated severe tricuspid regurgitation. J Thorac Cardiovasc Surg. 2023 Jul;166(1):91-100. doi: 10.1016/j.jtcvs.2021.07.036.