Outcome of Patients with Severe Functional TR According to Medical, Transcatheter or Surgical Treatment

Tricuspid regurgitation (TR) is a public health problem: moderate / severe TR are common, especially in ageing populations, and affect 4% of the population >75 years old, totaling approximately 1.6 million in the US and 3 million in Europe. The literature is consistent showing that TR is a serious condition, associated with morbidity (reduction in exercise capacity, heart failure) and mortality that increase with TR severity.

Current American College of Cardiology (ACC) / American Heart Association (AHA) and European Society of Cardiology (ESC) / European Association of Cardio-Thoracic Surgery guidelines (EACTS) guidelines recommend performing an isolated tricuspid valve surgery (ITVS) in patients with severe secondary (and primary) TR (with or without previous left-sided surgery), who are symptomatic or have right ventricle (RV) dilatation, in the absence of severe RV or left ventricular (LV) dysfunction and severe pulmonary vascular hypertension.

Contrasting with TR prevalence and the magnitude of the problem, the vast majority of patients are medically treated with diuretics to relieve their symptoms and a curative surgical treatment for isolated severe TR is seldom performed ITVS represents only 8% of all tricuspid valve (TV) surgeries and a tricuspid valve intervention is mostly performed at the same time that left-sided heart valve surgery. Thus, only 10% of patients admitted in France with a diagnosis of significant TR are referred for an intervention.

Reluctance to perform an ITVS can be explained in the one hand by the limited evidence that TR correction improves outcomes. Indeed, there is no large randomized multicentric study in the literature to compare medical vs surgical treatment of TR. A recent study did not show difference in long-term survival for patients who undergo surgical intervention compared to medical management alone but this was a non-randomized retrospective single-center study with a small propensity matched sample (62 patients in each group) and matching was performed according to parameters that are not specific to the RV. On the other hand, ITVS is associated to high observed in-hospital mortality rates (≈ 10% remarkably consistent in most series across the literature). In a large French multicentric registry of 466 patients gathering all consecutive patients who underwent a non-congenital ITVS on native valve for severe TR at 12 tertiary centers during a 11-year period (2007-2017), in-hospital mortality was 10% as in other series, but this average rate was hiding important disparities. Mortality rate was indeed markedly variable and was predicted by the severity of the pre-operative clinical, biological and echocardiographic presentation while TR mechanism / etiology had limited impact. As there is no dedicated STS risk score model for ITVS, and the logistic EuroSCORE and the EuroSCORE II were not designed for ITVS, the investigators have developed TRI-SCORE, a dedicated, simple and accurate risk score model to predict in-hospital mortality after ITVS that could guide the clinical decision-making process at the individual level. TRI-SCORE was based on eight clinical (age ≥70 years, NYHA functional class III-IV, right-sided heart failure signs, daily dose of furosemide ≥125 mg), laboratory (glomerular filtration rate <30 ml/min, elevated total bilirubin) and echocardiographic (LV ejection fraction <60%, moderate/severe RV dysfunction) parameters easy to ascertain and capturing the impact of TR on the RV, the liver and the kidneys. This risk score model, on a 0-12 points scale, provided both an excellent discrimination (C-index >0.75) and calibration with a predicted mortality rate ranging from 1% for 0 point to 65% for ≥9 points irrespective of TR mechanism / etiology. Half of patients were referred for an intervention late in the course of the disease with moderately (4-6) or severely elevated (>6) scores, and therefore high mortality rates. In contrast, low in-hospital and 1-year mortality rates (0% to 4%) were achieved in patients with low score (≤3). Our results suggest adopting a more pro-active approach for TV interventions, and to intervene earlier in the course of the disease in patients with severe isolated TR, irrespective of TR mechanism / etiology, before the occurrence of advanced / irreversible consequences such as severe RV dilatation / dysfunction, renal and liver failure, and intractable heart failure.

Transcatheter tricuspid valve interventions (TTVI) are still at an early stage with a large number of percutaneous TV devices currently under development. TTVI are mostly a repair, especially edge-to-edge repair, with promising initial results in the first real world registries with patients at high surgical risk. Therefore, TTVI, as a less-invasive alternative to surgery, may push for an extension of the number of patients treated.

What is the best treatment between medical, surgical or transcatheter therapy to consider and the best timing for each patient are not clearly defined. The aim of the study is to compare outcome of patients with significant functional TR according to medical, transcatheter or surgical treatment after matching per TRISCORE.