Moderate or severe tricuspid regurgitation (TR) is observed in 0.55% of the general population, with its prevalence increasing with age, affecting approximately 4% of patients aged 75 years or older. Secondary TR is more common (>90%) than primary TR. 

The management of TR has not historically been a primary focus for cardiac surgeons, often being underestimated due to the belief that addressing left-sided heart conditions would resolve secondary TR or that medical treatment would suffice. However, severe TR has been shown to be a strong predictor of prognosis across various disease states, particularly when compensatory mechanisms of the right ventricle (RV) develop. Over time, these mechanisms lead to changes in RV geometry, resulting in papillary muscle displacement, leaflet tethering, and/or coaptation deficit. Despite its high prevalence and poor prognosis, most patients (>90%) are undertreated, and management remains controversial due to variable surgical outcomes, sometimes failing to account for the anatomical complexity of the tricuspid valve. 

Tricuspid valve repair remains the preferred technique for patients requiring surgery and is primarily focused on annuloplasty using sutures or rings. The goal is to reduce the annular diameter. Numerous clinical, anatomical, and surgical predictors of annuloplasty failure have been identified, often related to anatomical changes in the leaflets. In these cases, annuloplasty alone may not suffice, necessitating consideration of additional techniques to restore valve competence. 

In December 2024, The Annals of Thoracic Surgery published an article on the long-term outcomes of clover repair (centralizing the free edges of all three leaflets) and edge-to-edge repair (resulting in a double-orifice valve) for addressing complex tricuspid regurgitation. This observational study, conducted at San Raffaele University Hospital in Milan by Dr. Maisano and Dr. De Bonis, demonstrated favorable outcomes for these techniques in the surgical treatment of complex tricuspid valve insufficiencies. 

The study recruited patients from 2001 to 2019. All preoperative, intraoperative, postoperative, and follow-up data were prospectively entered into a dedicated database and retrospectively analyzed. In addition to conventional statistical analysis, a competing risks proportional hazards regression model was employed. This model accounted for competing risks, defined as events that alter or prevent the occurrence of the primary event of interest. The Fine and Gray model was used to evaluate time to TR ≥2+ while considering death as a competing risk, as well as time to cardiac death with non-cardiac death as a competing risk. Hazards were reported as hazard ratios (HR) with 95% confidence intervals (95% CI). A p value < .05 was considered significant. Graphs were truncated at 16 years to ensure an adequate number of patients at risk. 

The study included 145 consecutive patients (57% female) with severe or moderately severe TR secondary to leaflet prolapse or flail in 115 patients (79%), tethering in 27 patients (19%), or mixed lesions in 3 patients (2%). The origin of TR was degenerative in 75% of cases, post-traumatic in 8%, and secondary to dilated cardiomyopathy in 17%. Previous cardiac surgery had been performed in 17% of the patients. 

The surgical technique employed was clover repair in 110 patients (76%) and edge-to-edge repair in 35 patients (24%), combined with annuloplasty in 95% of cases. A prosthetic ring was used in 64% of these cases, while sutures were used in 31%. The mean prosthetic ring size was 32 ± 2.7 mm. Concomitant procedures, primarily mitral surgery, were performed in 80% of cases. 

The in-hospital mortality rate was 5.5% (8 out of 145 patients). Follow-up was 98% complete, with a median follow-up duration of 15 years (interquartile range: 14–17 years), and the longest follow-up extending to 21 years. Overall survival at 16 years was 56% ± 5%. Previous cardiac surgery (HR = 2.83; 95% CI: 1.15–6.93; p = .023) and right ventricular dysfunction (HR = 2.24; 95% CI: 1.01–4.95; p = .046) were identified as significant predictors of mortality. 

The 16-year cumulative incidence of cardiac death, with non-cardiac death considered a competing risk, was 19.6%. Previous cardiac surgery (HR = 3.44; 95% CI: 1.23–9.65; p = .019) was the only predictor of this event. At the last follow-up, New York Heart Association (NYHA) functional class III or IV was reported in 14% of patients, compared to 51% at baseline (p < .0001). 

Regarding echocardiographic findings, 103 out of 134 patients (77%) had no or mild TR at the last follow-up. Moderate TR was observed in 20% of patients, and severe TR was present in 3% of patients, two of whom required reintervention. No significant tricuspid stenosis was detected. At 16 years, the cumulative incidence of TR ≥2+ with death as a competing risk was 23.8%. Previous cardiac surgery (HR = 2.30; 95% CI: 1.06–5.01; p = .04) emerged as the sole predictor of this event. 

COMMENTARY: 

The incidence of residual tricuspid regurgitation (TR) following tricuspid valve surgery varies between 10% and 30%, depending on baseline patient characteristics and the surgical approach, among other factors. Annular dilation is recognized as a preoperative predictor of residual TR. However, there is no consensus on other potential predictors, such as right heart failure, pulmonary hypertension, increased atrial volume, atrial fibrillation, rheumatic mitral valve disease, marked right ventricular (RV) remodeling or dysfunction, or a history of ischemic heart disease. Accurate identification of the mechanisms underlying TR through echocardiographic data is essential, requiring more focused attention comparable to that given to other valves. 

A study published in 2022 developed an algorithm for selecting the optimal surgical technique for tricuspid valve treatment based on specific characteristics. This study concluded that applying the algorithm resulted in lower rates of residual postoperative TR compared to other series. 

The principal finding of the current study, which motivated this commentary, was that the use of varied tools to address complex TR is both effective and durable, achieving a low recurrence rate of significant TR 15 years post-surgery. This group favors simplifying repair through clover or edge-to-edge techniques rather than more complex methods, such as leaflet resection or neochordae implantation, when annuloplasty alone is insufficient. These techniques provide an efficient and straightforward solution to restore valve coaptation. Furthermore, they suggest adding a small Teflon patch to the clover or edge-to-edge sutures in cases of particularly fragile tissue. 

It is worth noting the increasing competition from percutaneous approaches. Transcatheter methods have also extended to the tricuspid valve, with devices currently gaining popularity. However, the absence of concomitant annuloplasty may explain the suboptimal outcomes currently observed with transcatheter edge-to-edge tricuspid repair (TEER). Immediate results remain less satisfactory, with over 20% of patients showing severe or torrential TR post-procedure in recent series. 

In conclusion, when tricuspid regurgitation cannot be managed with annuloplasty alone, concomitant leaflet repair using clover or edge-to-edge techniques effectively restores valve competence and provides durable long-term results. When applied correctly, this approach can significantly enhance the surgical armamentarium of cardiac surgeons. It may also increase the repair rate, reduce the incidence of suboptimal early and late outcomes, and ultimately improve patient prognosis. 

REFERENCES: 

Sala A, Hahn RT, Kodali SK, Mack MJ, Maisano F. Tricuspid Valve Regurgitation: Current Understanding and Novel Treatment Options. J Soc Cardiovasc Angiogr Interv. 2023 Jul 5;2(5):101041. doi: 10.1016/j.jscai.2023.101041.

Lapenna E, Gramegna F, Del Forno B, Scarale MG, Nonis A, Carino D, et al. Long-term Results of Clover and Edge-to-Edge Leaflet Repair for Complex Tricuspid Regurgitation. Ann Thorac Surg. 2024 Nov;118(5):1072-1079. doi: 10.1016/j.athoracsur.2024.04.024.

Pintilie M. Análisis de riesgos competitivos [An introduction to competing risks analysis]. Rev Esp Cardiol. 2011 Jul;64(7):599-605. Spanish. doi: 10.1016/j.recesp.2011.03.017.

Rodriguez Torres D, Torres Quintero L, Segura Rodríguez D, Garrido Jimenez JM, Esteban Molina M, Gomera Martínez F, et al. Surgical management of tricuspid regurgitation: a new algorithm to minimise recurrent tricuspid regurgitation. Open Heart. 2022 Jul;9(2):e002011. doi: 10.1136/openhrt-2022-002011.