MedicalResearch.com: What is the background for this study?
-By definition a secondary MR concerns a normal valve or sub normal valve inside a dilated heart with poor LV function in a population of Heart failure patients. It is perfectly established today that secondary MR is a predictor of poor clinical outcomes of thissevere population.
-Therefore,it has been proposed to treat those regurgitation either by surgery (mainly the downsizing anuloplasty) or by percutaneous technique like the mitraclipwhich has been used more and more frequently recently.
-However, a beneficial effect on hardclinical outcomes has never been provedandwe still don’t know if those regurgitations need to be corrected or not, We still don’t Know if the regurgitation is the cause, the consequence or just a marker of poor prognosis.
-In this context according to the guidelines, there is a low level of evidence to support those treatments, and Europe and US Guidelines call for prospective randomized studies in this severe population.
And this excatly what we have done with MITRA-FR
MedicalResearch.com: What are the main findings? What should readers take away from your report?
Response: Over a 3-year period, patients were recruited to the study from 37 French centres; after centralised echographic Core Lab assessment, 304 patients were randomised in a 1:1 ratio to percutaneous mitral valve repair (pMVR) with the Mitraclip system in addition to optimal medical treatment (OMT; intervention group; n=152), or to OMT alone (control group; n=152). The primary efficacy endpoint was a composite of all-cause death and unscheduled hospitalisation for heart failure at 12 months.
At baseline, patients (mean age 70 years; 74% males) were severely symptomatic despite OMT, with 67% being in New York Heart Association (NYHA) class ≥III. The mean left ventricular ejection fraction was 33% and the functional mitral regurgitation (MR) was severe, with a mean regurgitant orifice area of 31 mm2. Patients were considered by a heart team to be ineligible for surgery.
The safety of the Mitraclip system was high, with no conversion to surgery and no procedural mortality. In addition, the rates of vascular complication (3.5%), tamponade (1.4%) and cardiac embolism/stroke (1.4%) were all acceptable.” The efficacy results also looked promising, he says. “The technical success of the procedure, according to Mitral Valve Academic Research Consortium criteria, was 96%. After 12 months, the MR was significantly reduced in the Mitraclip group, with 83% of MR grade 2 versus 0 at baseline.
However, despite the apparent safety and efficacy of the Mitraclip, the results did not translate into improved outcomes when compared to a control group.
There was absolutely no benefit of the Mitraclip in terms of survival rate or risk of rehospitalisation for heart failure at 12 months and the primary endpoint was negative.
Based on the confirmation of our statistical hypotheses and a follow-up of at least 99%, we can be confident that this conclusion is very robust. Moreover, the negative results seen in the primary analysis were observed also in the per-protocol analysis and all sub-group analyses.
The medical treatment in the two groups was particularly good according to the recommendations and both showed a similarly improved clinical status.
Mitraclip is safe and effective at reducing the MR but that the primary composite endpoint, including all-cause death and unplanned hospitalisations for heart failure at one year, was not significantly different between groups.
MedicalResearch.com: What recommendations do you have for future research as a result of this work?
Response: If our conclusion on the primary endpoint seems very robust, our analysis on a smaller sub-group of patients is more fragile. Therefore, more randomised studies are necessary to define possible sub-groups of patients who could really benefit from mitral valve repair.
MedicalResearch.com: Is there anything else you would like to add?
Response: MITRA-FR is a plea for more randomized studies for new percutaneous devices before a wide diffusion of those innovative techniques.
Jean-François Obadia, M.D., Ph.D., David Messika-Zeitoun, M.D., Ph.D., Guillaume Leurent, M.D., Bernard Iung, M.D., Guillaume Bonnet, M.D., Nicolas Piriou, M.D., Thierry Lefèvre, M.D., Christophe Piot, M.D., Ph.D., Frédéric Rouleau, M.D., Didier Carrié, M.D., Ph.D., Mohammed Nejjari, M.D., Patrick Ohlmann, M.D for the MITRA-FR Investigators.*
August 27, 2018
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