MitraClip Feasible, Safe, and Produces Promising Early Results in Tricuspid Regurgitation

LONDON, England—MitraClip was designed to treat mitral regurgitation but a handful of operators have been testing the device in the tricuspid valve. Results from a small series of patients presented here at PCR London Valves 2016 suggest that use of the device in this setting is safe and feasible, with promising early clinical outcomes.  

“Transcatheter repair of the tricuspid valve using the MitraClip is feasible, safe, and associated with good short-term durability,” researcher Jörg Hausleiter, MD (Medizinische Klinik und Poliklinik 1, Munich, Germany), said. “Furthermore, the successful interventional reduction of tricuspid regurgitation (TR) appears to be associated with a favorable short-term outcome in patients with isolated tricuspid repair or combined mitral and tricuspid repair.”

Less Regurgitation, Better NYHA Class at 30 Days

Hausleiter and colleagues enrolled 18 patients, who had a mean age of 80 and EuroSCORE II of 10 and were highly symptomatic. All patients were in NYHA class III (67%) or class IV (33%), and most had grade 3 or 4 tricuspid regurgitation (with 4 denoting massive or “torrent” TR with a vena contracta > 1.5 cm and loss of valve function). Six patients had isolated tricuspid regurgitation and 12 had combined mitral regurgitation (MR) and tricuspid valve disease, with both treated using MitraClip (Abbott Vascular) during the same procedure. Of note, two patients also had right ventricular pacemaker/ICD leads—a known trigger for tricuspid regurgitation.

To implant the clip, Hausleiter and colleagues employed what he called a “modified steering technique” using both transthoracic and transesophageal echocardiography that enabled the device to be placed at a perpendicular trajectory to the tricuspid valve. In all, 41 clips were placed (2.3 per patient), with 30 placed in the anteroseptal position and 11 in the posteroseptal.

No patients experienced in-hospital complications. One patient had a stroke within the first 30 days. This was a patient with combined TR/MR and very low ejection fraction at baseline who was found to have suffered from atrial thrombus formation in the left atrium. A second adverse event at 30 days was a single instance of repeat intervention in a patient with isolated TR who initially received three clips. One of the clips was found to have partially detached after 3 weeks. A new clip was successfully placed.

On echocardiographic follow-up, all patients experienced a reduction of TR of at least one grade, with 70% in grade 1 or 2 at 30 days. More than 70% were also in NYHA class II. In an analysis comparing isolated versus combined MR/TR, improvement in NYHA class was very similar between groups, with results for the isolated group equivalent to those of the MR/TR group and therefore similar to the overall results, although Hausleiter was careful to emphasize that the numbers were very small.

Hard to Tease Out Mechanisms

Asked by TCTMD whether there are outcomes data to support interventions in the tricuspid valve, Hausleiter pointed to the echocardiographic indicators of symptom relief in his series.

“These patients with isolated TR were very symptomatic and they had no other option: no surgery could have been performed in these patients, and their medications were fully optimized,” he said. “So there were no additional options. That’s why we thought we’d give this a chance in tricuspid regurgitation, and it worked very well.”

In the patients who underwent clip implantation for both their TR and MR, it’s less clear how to credit the improvement, Hausleiter said.

“Of course we cannot differentiate in this very small study if the improvement which we have seen is coming more from the mitral or from the tricuspid; this is very hard to differentiate. We do know that in patients with severe mitral and tricuspid disease that only a proportion—around 30%—demonstrate an improvement of their tricuspid regurgitation over time following mitral valve repair when nothing has been done to the tricuspid valve,” he observed. “But for the other 70%, the tricuspid regurgitation is persistent. That’s why we think that probably treatment [of TR] in those patients will help. We’re doing some more analysis and hemodynamic measurements to see if we can find an additional measurable effect in terms of hemodynamics if you are doing a combined treatment, but we are still in the early phase. We still need to define the patient population which would benefit most.”

Indeed, following Hausleiter’s presentation panelist Christoph Hammerstingl, MD (Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Germany), called the data “very impressive” but pointed to the two patients who had right ventricular pacemaker leads. Did these, he asked, complicate the procedure?

In response, Hausleiter gave a little laugh, saying, “Of course, pacemaker leads make this already very difficult procedure even more difficult.”

It’s important to understand at the outset where the tricuspid regurgitation is coming from, he continued. “If it’s coming from the lead then maybe it’s not the wisest idea to place a clip.” Instead, operators could consider removing the lead,” Hausleiter suggested. “But in those patients with pacemakers and tricuspid regurgitation that is not originating directly from the lead but from a different [etiology], then it is better probably to do the MitraClip.”

Another panelist in the session, Mamta Buch, MBChB, PhD (University Hospital of South Manchester NHS Foundation Trust, Wythenshawe, England), pointed out that “a lot of time thinking about mechanism” went into deciding how and in whom to use the MitraClip in the mitral position. Do we “have a clue,” she asked, as to what the mechanism might be in TR, in terms of approaching the problem with a MitraClip?

Here Hausleiter allowed that tricuspid regurgitation is even more variable than mitral regurgitation, and said this correlates with much more variable anatomical and physiological tricuspid valve orientation. As such, he predicted, a clip strategy may not be appropriate in all patients.

Elaborating to TCTMD, Hausleiter acknowledged the paucity of evidence supporting a mortality reduction with MitraClip in MR, let alone in the tricuspid position. “We have no prospective randomized controlled trials in this, of course, but we have some retrospective data to show that MitraClip is improving outcomes in terms of mortality in MR,” he reported. “Of course, what we would hope is that this can also be translated to some degree to patients with tricuspid disease, because we know that patients with severe TR have very poor outcomes.”

His understanding is that more than 100 patients have received the MitraClip in the tricuspid position at multiple centers, but whether these cases can be combined for analysis depends on how the clips were delivered. Hausleiter is demonstrating his “modified steering technique” here at PCR London Valves tomorrow. He also believes that Abbott has plans to formally study its clip in tricuspid regurgitation, with the aim of getting CE Mark for this indication.