Tricuspid regurgitation (TR) is a common concomitant condition in patients with severe aortic stenosis (AS). Although robust evidence regarding its management is still lacking, clinical practice guidelines recommend concomitant repair during left-sided valve surgery in cases of moderate TR (class IIa level of evidence) or severe TR (class I level of evidence). Transcatheter aortic valve implantation (TAVI) has expanded considerably in recent years because of its excellent outcomes, particularly in patients at high surgical risk. However, given the currently limited evidence supporting transcatheter tricuspid techniques, referral for TAVI usually means losing the opportunity to repair TR at the same time. The aim of this study was to analyze the long-term outcomes of patients with and without TR undergoing TAVI at a single center, and to identify which subgroups might benefit more from conventional combined surgery rather than isolated TAVI.

An observational, retrospective study was therefore performed, analyzing patients who underwent TAVI at the University of Michigan between 2012 and 2022 and selecting those with complete echocardiographic studies before and after the procedure. Baseline TR was classified into four grades: none, mild, moderate, and severe. Two main comparisons were established: patients with any degree of regurgitation versus those without TR; and patients with moderate-to-severe involvement versus those with mild or no TR. The main long-term outcomes assessed were changes in TR severity and late mortality. Finally, after univariable comparisons using chi-square and Wilcoxon tests, the actual impact on survival was determined using time-to-event analysis and a Cox proportional hazards regression model.

The cohort included 1668 patients, of whom 55% had TR (64% mild, 28% moderate, and 8% severe). Patients in this group were slightly older, had more comorbidities, and included a higher proportion of women than those with normal tricuspid valve function. Although the TAVI procedure showed excellent results, with very low complication rates, right-sided valve disease persisted in 70% of affected patients, and 30% of those without baseline TR developed it at a later stage. Only 15 patients (0.9%) subsequently required intervention. A subanalysis was performed in patients with moderate-to-severe TR, as these are the patients who would potentially have an indication for repair in the setting of surgical aortic valve replacement. In this group, TR persisted or worsened in 47% of cases, whereas in 14% it resolved completely without the need for any tricuspid intervention. In terms of overall survival, the presence of moderate or severe TR before the procedure markedly reduced median survival to 39 months, compared with 62 months in patients with mild or no TR. This negative impact was confirmed in sensitivity analyses performed separately in both high-risk and low-risk groups. Indeed, after statistically accounting for the effect of other comorbidities, moderate or severe TR proved to be an independent predictor of mortality, increasing the long-term risk of death by 39% (p = .004).

The authors conclude that TR does not improve after TAVI in a considerable proportion of patients, and that moderate-to-severe TR is associated with shorter long-term survival. Therefore, in the absence of universally reliable transcatheter tricuspid techniques, this concomitant valve disease should be a key factor when choosing between a transcatheter aortic valve approach and conventional surgery with associated tricuspid valve repair.

COMMENTARY:

This is a single-center observational study including a large cohort of patients undergoing TAVI. Concomitant TR was common and, in a substantial proportion of cases, did not resolve after valve replacement. TR was moderate or severe in 20% of patients, and in almost half of them the valve disease did not improve after aortic valve intervention. Patients with moderate-to-severe TR before TAVI were shown to have poorer survival than those with lower-grade TR. However, no statistically significant differences in mortality were found when comparing patients whose TR resolved completely after TAVI with those in whom it persisted or progressed.

It should be noted that TR was functional in all cases. The pathophysiological basis lies in the fact that increased afterload in severe aortic stenosis leads to higher pulmonary pressures and, eventually, right-sided chamber overload. Although correction of the primary cause would theoretically be expected to reduce pulmonary pressures and improve TR, this did not occur in almost half of the cohort. This may be explained by the usual profile of patients referred for TAVI, who are often complex and have long-standing valve disease, leading to chronic right-sided overload and pulmonary hypertension that may become irreversible. The influence of TR on mortality remains a matter of debate. It is unclear whether the poorer prognosis of these patients is due to the valve dysfunction itself or to the irreversibility of the underlying cardiopulmonary structural abnormalities that cause it. Evidence suggests that quantitative assessment of pulmonary pressures, reversibility of pulmonary hypertension, and parameters of right ventricular function, such as TAPSE or strain, are better predictors of long-term mortality than TR grade in isolation.

On the other hand, transcatheter repair techniques for the tricuspid valve are still not widely available and lack robust long-term evidence. For this reason, one could argue that, in low-surgical-risk patients with severe AS and significant TR, combined surgery appears to be the most appropriate option. However, without wishing to oversimplify the issue, this study only shows that patients with residual valve disease after correction of the other valve by TAVI have a poorer prognosis. Just as evidence has shown that transcatheter repair of TR has no proven impact on survival, it has also been difficult to demonstrate that the effect of surgery is different. Moreover, in the study itself, there were no survival differences between patients in whom TR corrected spontaneously and those in whom it did not.

Overall, this study reinforces the importance of individualized decision-making in this type of patient through a multidisciplinary team. Although we lack sufficient evidence for TR alone to dictate the therapeutic strategy for aortic valve disease, the findings show that it is a critical factor to consider, especially in patients at low surgical risk. Even so, I believe that future studies assessing the prognostic impact of pulmonary pressure reversibility and right ventricular function in these patients would be of great interest, as they could help establish more accurate prognostic risk scores and optimize decision-making.

REFERENCE:

Carducci J, Fu W, Wagner C, Proebstle J, Woodford J, Green C, et al. Worse survival in transcatheter aortic valve replacement with untreated tricuspid regurgitation: Implications for surgical intervention. J Thorac Cardiovasc Surg. 2026 May;171(5):1049-1056. doi: 10.1016/j.jtcvs.2025.11.026. Epub 2025 Dec 19. PMID: 41422881.