Functional Mitral Regurgitation

Perspectives beyond Mitraclip

The discussion about the interventional treatment of mitral regurgitation has already been deepened here on our platform, in several posts regarding echocardiographic aspects, clinical characteristics and technical interventionist concepts. That functional mitral regurgitation is complex and derived from dysfunction of several components of the valve apparatus is no longer new, but trials that analyzed the intervention were very limited only to the edge-to-edge device (MitraClip).

The mere presence of mitral regurgitation in patients with heart failure with reduced ejection fraction is a negative prognostic factor and in view of that, seeking to correct or even decrease the degree of this reflux seems to be interesting.

Using a percutaneous annuloplasty device, Carillon, there was a substantial improvement in hemodynamic and echocardiographic parameters in individuals undergoing correction over a year. There was a favorable remodeling with an improvement in the degree of regurgitation.

Criteria for clinical improvement were also achieved, such as better capacity for physical exertion marked by the prevalence of high functional class I and II, better performance in the 6-minute walk test and quality of life questionnaires. However, these criteria were also better in the control group, which consisted only of optimized clinical treatment.

Reasons for not having a statistical difference between these groups when analyzing clinical variables were raised, such as the absence of blinding patients. Questioning bias arises in a patient known to be participating in institutional research.

This work differs from the famous COAPT and MITRA-FR studies, in that it selected patients with moderate degree of regurgitation onwards. This raised an interesting question, since the fact that we did not find a positive result for mortality when comparing the groups can be justified for this reason, after all, moderate mitral regurgitation, traditionally does not worsen the prognosis to the point of justifying an intervention. In contrast, early intervention appears to have shown a protective effect on hemodynamic deterioration, as the parameters of patients who underwent intervention were much higher than that of the control group.

As this work was designed only to demonstrate the hemodynamic effect of the procedure, the same group is following a prospective cohort for 5 years to be able to adequately analyze the effect on survival and clinical outcomes.

What is interesting is that the treatment focused on the mitral valve annulus presents safety and good hemodynamic results, opening yet another window of treatment opportunities for patients with functional mitral regurgitation, in addition to the well-publicized Edge-to-Edge.

     Suggested literature:

1 – Witte KK, Lipiecki J, Siminiak T, et al. The REDUCE FMR Trial: A Randomized Sham-Controlled Study of Percutaneous Mitral Annuloplasty in Functional Mitral Regurgitation. JACC Heart Fail. 2019; 7 (11): 945‐955.

 

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