Introduction
The tricuspid valve (TV) was long known as the ‘forgotten valve’, because tricuspid regurgitation (TR) was considered resolved by left disease surgery. However, various researchers found that left heart valve treatment did not correct tricuspid annular dilatation or improve right ventricular (RV) function.1 Follow-up studies also observed TR persistence or progression in patients who had not undergone TV surgery and even in those who had. For instance, Shiran and Sagie found that only 33% of severe/moderate TR cases became mild after mitral valvuloplasty.2
TR is frequent in patients with concomitant heart disease, especially valve disease. The prevalence of TR is 15% overall and higher in patients with left disease, and it is the most frequent complication of mitral disease. In cases of heart failure (HF), TR grade >2/4 has been reported in 35% overall, in 30% of those with severe mitral regurgitation, and in 50% of those treated with mitral valve surgery.3
The surgical technique of choice remains under debate,4–7 although valve repair is the most common approach, especially rigid ring annuloplasty, with reports that 15% of the patients have residual TR in comparison to 20%–35% of those undergoing other procedures.1 Additional techniques applied in cases of marked valve deformity or ventricular remodelling include anterior leaflet extension, neochordae implantation, decalcification or commissuroplasty. Prosthetic replacement is a last resort.
The presence of residual TR and its grade are independent predictors of mortality, which is more likely with higher severity. The persistence of TR grade 3–4/4 after mitral valve replacement is associated with worse functional class and with higher mortality rates for HF and all causes.8
The frequency of residual TR after tricuspid surgery ranges between 10% and 30%9 according to the baseline characteristics of patients and the surgical approach, among other factors.10–12 In one follow-up study, only 32% of patients had no residual TR at 3 months postsurgery and only 22% at 5 months, while TR grade 3/4 was recorded at the same time points in 11% and 17% of patients, respectively.13 TR grade 3/4 was observed in 12% of patients after rigid ring annuloplasty, 16% after flexible prosthesis implantation, 24% after De Vega annuloplasty, 44% after periguard annuloplasty, and 19% after Kay’s annuloplasty.13
Annulus dilatation is known to be a preoperative predictor of residual TR. However, there is no consensus on other potential predictors, including the presence of right HF, pulmonary hypertension, increased atrial volume, atrial fibrillation (AFib), rheumatic mitral valve disease, marked RV remodelling/dysfunction or a history of ischaemic heart disease.14–16 There is wide agreement on the therapeutic response to severe TR, but the approach to lesser grades remains controversial. Thus, American clinical practice guidelines17 centre on severe or progressive TR, while European guidelines18 include recommendations for lower grades associated with certain predictors of residual TR. The evidence underlying European guidelines includes data on: the association of severe TR with congestive HF19; poor outcomes in isolated severe TR cases attributed to late patient management20; good survival rates after combined tricuspid and mitral valve surgery,21 and the predictive capacity of annulus size.1 22 Brescia et al23 followed European clinical practice guidelines in patients with functional TR and reported absent or only moderate TR in a large proportion of patients, with the persistence of good RV function. Other authors underscored the need for careful patient selection to improve outcomes.22 In contrast, one study found that survival was not improved by surgery in comparison to medical treatment.24 American guidelines cite multiple references related to TR of different grades/etiologies and associated predictive factors; however, almost all focus on the study of severe TR.
With the above background, we hypothesised that the TR rate at 1 year would be reduced by selecting the surgical approach in accordance with a set of preoperative clinical and echocardiographic variables. A corresponding algorithm was implemented in this study, following up patients during 1 year after TV surgery to evaluate TR recurrence. The primary objective of the study was to assess the efficacy of this novel algorithm for surgical intervention to TR, considering the residual TR as primary endpoint. Secondary objectives were to determine the mortality for all causes and for cardiovascular disease with implementation of the algorithm and to evaluate predictors of TR at 1 year and predictors of early and late mortality.