Devices for Functional MR: One Clip, Two Clip, Three Clip, Four?

12th Biennial Meeting of the International Andreas Gruentzig Society:  Rio de Janeiro - February 2-6, 2014

From SESSION 2 — Structural

    Moderator:      Jim Zidar
    Panelists:      Steve Bailey, Robert Bersin, Larry Dean, Bill O’Neill

Framing the question at hand, what is the state of the current knowledge?

There are four million people with moderate or severe mitral regurgitation, whose mortality increases in the presence of ischemic heart disease or dilated cardiomopathy.  Mitral valve disease is more diverse than aortic and may involve degenerative leaflets, chordal abnormalities, papillary muscle dysfunction from ischemia or rupture, LV dilatation, or congential anamolies.   Is the Mitral Clip the most appropriate approach for functional MR?  Unfortunately, few patient (only 5-8%) may be eligible. Finally, will any disease beyond functional MR be available in the near term?  

What are the Gaps in the current knowledge?

When do we intervene and what are the markers for intervention?  Who benefits most from this technology?  A mortality trial is required.  Are there limits to multiple clip use and the amount of annular reduction?  If chords are damaged, can they be repaired?  Definite therapy may require multiple approaches- how do we evaluate our options?  Should the annulus be approached separately from the valve?

Our Summary and Recommendations:

While the Mitral Clip is an acceptable first step, alternative devices need to be developed for functional MR that reduce annular dimensions. Collaboration between heart failure and EP specialists will be necessary for long-term success. The timing of the decision to intervene should be more clearly defined. Clinical trials to determine the benefit of this strategy over minimally invasive MR repair should continue.