Author + information
- Department for General and Interventional Cardiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
- ↵∗Address for correspondence:
Dr. Florian Deuschl OR Prof. Ulrich Schäfer, University Heart Center, University Hospital Hamburg-Eppendorf, Department for General and Interventional Cardiology, Martinistrasse 52, 20246 Hamburg, Germany.
In recent years, we have come to appreciate that the dysfunctional tricuspid valve deserves more respect, and the “forgotten valve” has become an area of emerging interest to interventional cardiologists and surgeons. Prevalence of tricuspid valve regurgitation (TR) in the adult population is high (1). For most cases (80% to 90%) of significant TR, the etiology of dysfunction is considered secondary—a consequence of pressure and/or volume overload from pulmonary hypertension or left-sided heart failure thereby leading to tricuspid annular dilatation predominantly in the area of the free wall (2,3).
The diagnosis of TR is often incidental because symptoms and clinical manifestations do not develop until late or advanced stages. Echocardiographic imaging is of decisive importance to understand the cause, extent, and stage of TR. It is known that untreated severe TR is associated with a high mortality, approaching 30% to 40% within the first year (2). When TR is treated, the conservative standard therapy consists of heart failure medications, mainly diuretic agents (4). If surgery is performed for TR, it is usually done only when severe symptoms appear or when the concomitant mitral valve (MV) or aortic valve (AV) disease requires surgery (5). Unfortunately, tricuspid valve surgery under certain patient conditions is associated with substantial early and late mortality (6). Last, but not least, patients with left-sided heart failure (reduced left ventricular function, mitral regurgitation [MR], or aortic stenosis [AS]) have a worse outcome of medical and interventional, as well as surgical, therapy when concomitant TR is present (7,8).
With these important points in mind, there is an increasing need for all patients treated with a transcatheter technique on the MV or AV, who have concomitant TR, to get comparable interventional treatment consideration for the tricuspid valve. Due to the clinical significance of TR, catheter-based tricuspid valve treatment has become one of the next big targets in structural heart disease therapy, and there is an ongoing debate whether earlier operative or interventional treatment of TR might be favorable for outcome.
In this context, it is unfortunate that long-term data on surgical tricuspid valve repair and replacement are scarce—randomized clinical trials do not exist. Although interventional treatment of MR with the MitraClip (Abbott Vascular, Santa Clara, California) and AS with transcatheter aortic valve replacement for high-risk MR and intermediate or high-risk AS patients have entered European and American practice guidelines, development of interventional treatment of TR is still in an experimental phase. In this regard, catheter-based annular reduction (band), edge-to-edge therapy (clip), a simple reduction of central coaptation failure (spacer), annular tensioning, or suture-based bicuspidalization, as well as orthotopic or heterotopic valve implantation, are currently being studied with mostly promising short-term preclinical and clinical outcomes despite a prohibitive surgical risk in most studies.
In this issue of JACC: Cardiovascular Interventions, Besler et al. (9) provide a retrospective analysis of a nonrandomized study of 117 patients. Patients were treated with an edge-to-edge repair technique (MitraClip) in an off-label use on the tricuspid valve for severe or torrential functional (97%) TR and in the majority of cases with concomitant edge-to-edge treatment of the MV. The study included patients with an elevated risk for surgery (STS for MV repair 5.3%) and severe symptoms (97% with NYHA [New York Heart Association] functional class III to IV). The anteroseptal commissure was the primary target of the intervention in 92%. Procedural success, defined by the authors as a reduction of 1 or more grades of TR, was achieved in 81% of patients. A successful repair of TR translates into lower mortality and reduced hospitalization, irrespective of whether isolated or combined with treatment of MR. Improvement of NYHA functional class was evident in 76% of patients. The 6-min walk test distance improved by 29%, and an improvement of at least 25 m was observed for most patients (72%). The authors report a statistically significant reduction of TR vena contracta and effective orifice area. Interestingly, reduction of TR by at least 1 grade was the only predictor of freedom from the combined outcome endpoint (mortality and hospitalization), as well as independently for freedom of death or hospitalization for heart failure. Interestingly, coaptation gap size (≤10 mm) and anteroseptal jet location were defined as predictors of procedural success. The authors were also able to calculate cutoff values above which TR repair with the edge-to-edge system is not favorable (coaptation gap >10 mm, TR effective residual orifice area >0.6 cm2; tenting area >2.1 cm2, and TR vena contracta >11 mm).
Clearly, the relatively small number of patients, the retrospective, nonrandomized nature of the study, and the lack of control group on maximal medical therapy are limitations. Also, the definition of procedural success (improvement in TR by at least 1 grade) might at first seem rather unambiguous. However, it is quite acceptable considering this early phase and the limited knowledge of interventional tricuspid valve repair. In the future, the aim of interventional treatment of TR should be a complete abolition or at least a reduction to mild TR. The rather high mortality (21% at roughly 6-month follow-up) demonstrates the complicated clinical conditions in many of the investigated patients, and is not substantially different from medical/conservative treatment. Hence, procedural cost considerations will need to be balanced against the gain in quality-of-life improvements.
In summary, there is an undeniable need for interventional tricuspid valve therapy for TR. Besler et al. (9) elegantly prove not only feasibility of an edge-to-edge repair in TR patients, they also show the direct benefit of procedural success on outcome and provide the first evidence regarding predictors for favorable outcome of interventional TR treatment. A procedural success of 81% is remarkable when considering the challenges of tricuspid valve imaging and the fact that the device used is not specifically designed for tricuspid valve intervention. Demographic evolution in Western countries is generating the need for better understanding of TR, reliable imaging parameters for the same, and evidence for individualized patient treatment. The future will tell whether transcatheter repair or replacement will become the preferred method for high-risk surgical patients with significant TR. Inevitably, interventional treatment of heart valves will steadily improve and will eventually replace open cardiac surgery for many indications. This development is strongly influenced monetarily by the industry on one side, on the other, however, by human curiosity and the strive to constantly improve treatment by scientists and doctors. This technology development process will undoubtedly accelerate and will be ultimately successful in favor of the patient when the heart team (cardiologist, cardiac surgeon, echocardiographer, anesthesiologist, and radiologist) works in close relationship contributing individual knowledge and accepting future heart valve treatment as a team approach.
↵∗ Editorials published in JACC: Cardiovascular Interventions reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Interventions or the American College of Cardiology.
Dr. Deuschl has received speaker honoraria from Abbott. Prof. Schäfer is a proctor and consultant to Abbott Vascular and has also received speaker honoraria, travel support, and study grants from Abbott Vascular.
- 2018 American College of Cardiology Foundation
- Nath J.,
- Foster E.,
- Heidenreich P.A.
- Tornos Mas P.,
- Rodríguez-Palomares J.F.,
- Antunes M.J.
- Kalbacher D.,
- Schäfer U.,
- von Bardeleben R.S.,
- et al.
- Thourani V.H.,
- Forcillo J.,
- Szeto W.Y.,
- et al.
- Besler C.,
- Orban M.,
- Rommel K-P.,
- et al.