‘Europe Isn’t Waiting’: MitraClip Moves Into New Niches, Big and Small
PARIS, France—Another international meeting, another opportunity for MitraClip enthusiasts to demonstrate the benefits of the device in new patient subgroups as the field waits on the ongoing randomized controlled studies. Top of mind are any results in functional mitral regurgitation (MR) patients, who now make up the majority of those receiving the device in Europe—and increasingly in the United States and elsewhere—despite the fact that trials studying this population have not yet wrapped up.
In the United States, based on the EVEREST II trial, the MitraClip (Abbott Vascular) is only approved for use in symptomatic patients with primary, degenerative MR who are at high-risk for surgery. European guidelines note that MitraClip use is “feasible” in both primary and secondary MR but that long-term data are lacking.
On the final day of EuroPCR 2016, Julia Seeger, MD (University of Ulm, Germany), presented an analysis of 210 patients treated with the MitraClip at her institution, comparing early outcomes in the 105 consecutive functional MR patients with those in 105 consecutive degenerative MR patients. The comparison was made post-learning curve, after operators had become proficient in the procedure.
There were important differences in the groups at baseline, Seeger noted. Functional (secondary) MR patients were younger with lower mean ejection fractions and greater left ventricular dimensions. They were also more likely to be male and more likely to have had a previous MI. All patients in both groups had MR grade 3 or 4 at baseline.
Both groups, however, saw improvements in MR grade following the procedure, with MR grade falling to within the range of 0-2+ in more than 95% of patients in both groups at 30 days. Three patients in the secondary MR group died within the first month and one patient had a stroke. There were four deaths and no strokes in the primary MR patients. No major vascular or cardiac complications occurred in either group. Improvements in NYHA grade occurred in both groups, but were significantly greater in the primary MR patients: -1.7 in the secondary MR group and -2.2 in the primary group (P = 0.002).
“Percutaneous mitral valve repair using the MitraClip device is safe and effective in patients with primary and secondary MR with a low rate of 30-day safety events, according to the MVARC criteria,” Seeger concluded. “Functional improvement at 30 days, however, was significantly higher in primary MR.”
Small Series Shows Promise
Following Seeger’s presentation, a number of Italian investigators offered a glimpse at MitraClip’s performance in other niche settings.
Researchers led by Marianna Adamo, MD (Spedali Civili, Brescia, Italy), examined the MitraClip in five patients with acute ischemic MR complicating acute myocardial infarction who presented in cardiogenic shock. One patient died of noncardiovascular causes but in three out of four patients, MitraClip was associated with significant improvement in MR out to 2 years. The lone patient whose MR showed only modest improvement over follow-up also had concomitant aortic regurgitation, the authors noted—a factor they believe to be responsible for the lack of improvement in this case.
A separate group led by Nicola Buzzatti, MD (San Raffaele Scientific Institute, Milan, Italy), examined patients with radiation-induced mitral regurgitation, the incidence of which is growing, they noted. In six patients with functional MR typically due to fibrocalcification of the intrathoracic structures, MitraClip implantation successfully improved NYHA class in five out of six patients followed for a median follow-up of 29 months (one patient was lost of follow-up). There were no deaths, no rehospitalization due to heart failur, and no clip detachment.
Finally, Giuseppe Bruschi, MD (Niguarda General Hospital, Milan, Italy), and colleagues looked at the use of the MitraClip in 22 high-risk patients with refractory heart failure and LVEF ≤ 35% otherwise being managed palliatively or considered for heart transplantation. In these patients, according to presenter Stefano Nava, MD, PhD, MitraClip appeared to significantly reduce MR, improve patient symptoms, and reduce hospitalizations but did not boost survival. Indeed, only six patients were alive at 1 year, prompting session co-moderator Georg Nickenig, MD (Heart Center, University of Bonn, Germany), to comment that it may be time for futility discussions around the MitraClip, similar to discussions in the early days of TAVR for aortic stenosis. “It doesn’t make sense to use an elaborate technique that is so expensive if we won’t change the course of the patient,” he said. “Sometimes we need to step back.”
Improved Symptoms Drive Usage
Speaking with TCTMD following the presentations, Nickenig commented that the post-radiation patients and the post-MI patients both represent “a niche—only a few patients will be applicable . . . we don’t see many of these in our daily practice,” although these series are informative. “Most patients we see will be functional MR secondary to heart failure, and that’s what’s going on right now already, at least in Europe and to some extent in the US.” This is despite the fact that the COAPT trial, MITRA-FR, and the halted RESHAPE HF trials have yet to deliver answers.
Asked whether he thinks these trials will support what has already become practice, Nickenig gave a wry laugh. “I don’t know, we’ve been wrong so frequently in the past. We should wait for the data,” he said. At issue is whether the device actually improves survival and limits heart failure hospitalizations, or—as the accumulating data suggest—serves mainly to assuage symptoms.
“Europe,” he acknowledged, “isn’t waiting” for the randomized clinical trial results, “because the patients are doing fine symptomatically after the procedure, so they are calling for the therapy themselves.” RESHAPE HF, he noted, was stopped prematurely because no patient wanted to be randomized to medical therapy.
- Adamo, M. Acute ischaemic mitral regurgitation: safety and efficacy of MitraClip implantation. Presented at: EuroPCR 2016. May 20, 2016. Paris, France.
- Buzzatti N. Transcatheter mitral repair for radiation-induced mitral regurgitation: a case series. Presented at: EuroPCR 2016. May 20, 2016. Paris, France.
- Nava S. Effectiveness of MitraClip therapy in patients with refractory heart failure. Presented at: EuroPCR 2016. May 20, 2016. Paris, France.
- Seeger J. Comparison of percutaneous mitral valve repair in functional and degenerative mitral valve regurgitation using the Mitral Valve Academic Research Consortium criteria. Presented at: EuroPCR 2016. May 20, 2016. Paris, France.
- Seeger, Adamo, and Schiavi report no conflicts of interest.
- Nickenig reports honoraria or advisory board participation with AGA, AstraZeneca, Bayer, Berlin Chemie, Biotronic, BMS, Boehringer Ingelheim, Daiichi Sankyo, Edwards, Medtronic, Novartis, Pfizer, and Sanofi Aventis.