Ringless MitraClip therapy: is it time to learn to give up?

Abstract

I have read with interest the article by Taramasso et al. [1]. They compared retrospectively the efficacy of the MitraClip (percutaneous edge-to-edge [E2E] procedure) with surgical treatment (E2E stitch plus annuloplasty) in patients with severe functional mitral regurgitation (FMR) and heart failure. They concluded that MitraClip therapy is a good alternative, particularly in patients who are not amenable to surgery. It could be that MitraClip improves safety because of its percutaneous deployment. However, one cannot forget the good outcome of the E2E stitch especially when ring annuloplasty is included as a part of the procedure [2]. For those of us who have learned the traditional concepts of Dr Carpentier’s ‘old school’, the use of annuloplasty ring is a requirement in any mitral valve repair [3]. Indeed, the same Milan group found that the best outcome is achieved when E2E is used with ring annuloplasty [2]. Although Maisano et al. [4] demonstrated that it is possible to perform E2E repair without annuloplasty in 29 cases of FMR with an acceptable outcome, a limitation of their study is the small sample size that does not allow to make any firm inference. In addition, we know that, in chronic ischaemic mitral regurgitation, the mitral valve annulus is misshaped and deformed, and tethering forces arising from the adversely remodelled left ventricle towards the mitral valve are responsible for mitral valve regurgitation [5]. So, if we are to learn from our failures, one should conclude that the reshaping of the mitral valve annulus by means of a prosthetic ring is an absolute ‘must’ in the treatment of FMR. This does not mean that we do away with all we have learned about ring annuloplasty. I would propose that long-term follow-up studies are needed to clarify the safety and efficacy of the percutaneous MitraClip therapy without annuloplasty ring for FMR. Keeping in mind that the percutaneous mitral valve annuloplasty has its own shortcomings [6], the role and place of MitraClip therapy in the treatment of FMR are yet to be elucidated.