Author + information
- Published online September 3, 2018.
- Daniel Braun, MD∗ (, )
- Mathias Orban, MD,
- Martin Orban, MD,
- Christian Hagl, MD,
- Steffen Massberg, MD,
- Michael Nabauer, MD and
- Jörg Hausleiter, MD
- ↵∗Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Marchioninistraße 15, D-81377 München, Germany
Transcatheter edge-to-edge repair has been shown to be an alternative treatment option in selected inoperable patients with severe tricuspid regurgitation (TR) (1). However, the optimal clip placement strategy remains to be established. Reduction of TR can be achieved by a triple-orifice technique (TOT) (Figures 1A and 1B), where clips are ideally placed centrally between the septal and anterior tricuspid leaflet as well as the septal and posterior tricuspid leaflet. Alternatively, a bicuspidalization technique (BT) (Figures 1C and 1D) can be applied, where clips are placed between the septal and anterior tricuspid leaflet.
We retrospectively analyzed 69 consecutive symptomatic patients treated for severe, predominantly secondary TR at the Munich University Hospital from March 2016 to September 2017 to compare the previously mentioned clip placement strategies. In 44 patients the TOT was used while in the remaining 25 patients the BT was applied. The BT was primarily applied in the initial patients and the TOT was subsequently favored.
Mean patient age was 78 ± 11 years with a Society of Thoracic Surgeons score of 7 ± 7. Most patients suffered from pulmonary hypertension as expressed by a transtricuspid gradient of 36 ± 15 mm Hg. Sixty-one percent of patients were treated simultaneously for severe TR and severe mitral regurgitation. Baseline characteristics did not differ between groups except for a higher Society of Thoracic Surgeons score in the BT group (9.7 ± 9.8 vs. 5.5 ± 4.8; p = 0.04).
Acute procedural success rates (i.e., TR grade ≤2) were 93% in the TOT group and 84% in the BT group, respectively (p > 0.25). The mean number of implanted clips was 2.4 ± 0.6 in the TOT group and 1.9 ± 0.7 in the BT group (p = 0.002). No in-hospital major adverse cardiac or cerebrovascular events were observed.
Thirty-day follow-up was available in 88% of patients. A persistent reduction of TR ≤2 was demonstrated in 82% and 77% of patients in the TOT and the BT groups, respectively (p = 0.74). Clip implantation was associated with an increase in tricuspid inflow gradient from 1.1 ± 0.6 mm Hg at baseline to 1.9 ± 0.8 mm Hg at follow-up (p = 0.001), which did not differ between groups.
In line with these results, quantitative parameters of TR including vena contracta, effective regurgitant orifice area and regurgitant volume improved to a similar extent in both groups. Right ventricular function was stable in both groups according to tricuspid annular plane systolic excursion (16.1 ± 4.3 mm at baseline vs. 15.4 ± 4.1 mm at 30 days; p = 0.12). While tricuspid annulus diameter significantly decreased from 47 ± 7 mm to 42 ± 7 mm in the TOT group (p = 0.002), the change in the BT group was less pronounced (44 ± 5 mm at baseline vs. 42 ± 7 mm at 30 days; p = 0.1).
TR reduction appeared to be associated with clinical benefit at 30 days. The rate of patients in New York Heart Association functional class ≥III could be reduced from 100% to 53% in the TOT group and from 100% to 35% in the BT group (p = 0.2).
Considering adverse events, we observed 1 stroke and 1 single-leaflet clip detachment in the BT group.
Considering all 69 patients, we observed a significant increase in the 6-min walking distance from 196 ± 98 m at baseline to 233 ± 113 at follow-up (p = 0.007), a significant improvement in quality of life as expressed by a reduction in the Minnesota Living with Heart Failure Questionnaire score from 44 ± 19 at baseline to 32 ± 17 at follow-up (p = 0.001) and a numerical decrease in the level of N-terminal pro–B-type natriuretic peptide from 11.228 ± 26.803 pg/ml at baseline to 9.214 ± 19.463 pg/ml at follow-up (p = 0.18). Results were comparable in both groups.
This study demonstrates that transcatheter edge-to-edge repair of severe TR can be successfully performed using the TOT as well as the BT with a comparable clinical benefit at 30-day follow-up. These results are in line with preclinical data, where the cardiac output could be significantly increased by placing 2 clips into the anteroseptal commissure and by the concomitant placement of clips into the anteroseptal as well as the posteroseptal commissure (2).
However, the TOT might be more efficient in reducing septolateral tricuspid annulus diameter by exerting pulling forces on both the anterior and posterior circumference of the tricuspid annulus. This treatment strategy could be superior to the BT, as the TOT achieves a direct reduction of the coaptation gaps and, at the same time, counteracts annular dilatation, which primarily occurs in the anterior and posterior circumference of the tricuspid annulus.
The small number of patients and the lack of a randomized trial design are major limitations of this study. Therefore, the results need to be considered as “hypothesis generating.” However, this first systematic comparison of 2 different clip placement strategies for tricuspid edge-to-edge repair might provide the basis for further randomized trials.
Please note: Klinikum der Universität München has received grant support from Abbott Vascular. Drs. Braun and Nabauer have received speaker honoraria from Abbott Vascular. Dr. Orban has received speaker honoraria from Roche; and travel grants from Roche and Abbott Vascular. Dr. Hausleiter has received speaker honoraria from Abbott Vascular and Edwards Lifesciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation
- Braun D.,
- Nabauer M.,
- Orban M.,
- et al.
- Vismara R.,
- Gelpi G.,
- Prabhu S.,
- et al.