Mitral regurgitation (MR) is the second most common valvular disorder in Europe.1 Its diagnosis, classification and treatment are standardized by the joint guidelines of the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery (ESC/EACTS).2 Surgical repair is the reference treatment,2 but around half of patients with severe MR are denied surgery3 due to advanced age, ventricular dysfunction or other comorbidities or contraindications. There is thus a clear need for less invasive alternatives. In the last twenty years, various percutaneous devices have been developed, and many concepts and approaches have been tested, including direct and indirect annuloplasty, the NeoChord valve repair device, right ventricular remodeling, leaflet plication, and percutaneous valve replacement. However, to date only one device has progressed beyond the stage of randomized clinical trials4 and been recommended by regulatory bodies2,5,6: the MitraClip system (Abbott Vascular, Menlo Park, CA, USA). This device reproduces percutaneously the Alfieri surgical technique, in which a double-orifice valve is created by plicating the mid segments of the anterior and posterior leaflets. The MitraClip has a complex delivery mechanism by which, via a transseptal approach, one or more cobalt chromium clips are implanted to bring together the mid segments (A2 and P2 scallops) of the valve leaflets. Over 20 000 MitraClip procedures have been performed worldwide. The EVEREST I and II trials in the USA included a pilot stage to evaluate safety and feasibility, a registry of patients at high surgical risk, and a randomized trial comparing MitraClip therapy with conventional surgery,4,7–9 and were followed by the REALISM continued access registry. In October 2013 the US Food and Drug Administration (FDA) approved use of the MitraClip in patients with symptomatic degenerative MR and high surgical risk,5 while in Europe the device received CE Mark approval in March 2008. Its use has grown exponentially, mostly in patients with functional MR, advanced age and high surgical risk. The ACCESS-EU registry (Phase I and II) included around 1000 interventions.

In the 2012 ESC/EACTS guidelines on the management of valvular heart disease, the MitraClip was given a class IIb recommendation for symptomatic functional or degenerative MR in patients judged inoperable or at high surgical risk.2 The technique has thus, despite its limitations, overcome various hurdles in the evaluation process and has won its place in clinical practice.

In Portugal the first MitraClip procedure took place on January 9, 2013 at Hospital de Santa Maria (Figure 1), and others followed at Hospital de Santa Marta and Hospital de Vila Nova de Gaia. This was relatively late compared to other European countries, five years after the device received CE Mark approval and in the same year as its approval by the FDA. Its growth has been slow but steady: in the first half of 2015 around a hundred procedures were performed in the Iberian Peninsula, about 20% of them in Portugal. The results presented by Cacela et al. in this issue of the Journal10 reflect real-world experience and are comparable to those of large European registries, including the international Transcatheter Valve Treatment Sentinel Pilot Registry11 and the German TRAMI registry.12–14 The three Portuguese centers are expected to participate in the important international RESHAPE-HF 2 trial, confirming the consistent quality of their work in this area. The primary aim of this randomized trial is to assess the impact of the MitraClip on mortality and rehospitalization for heart failure in patients with severe symptomatic functional MR compared to optimal standard of care therapy. It has the potential to bring about profound changes in the treatment of patients with impaired systolic function and secondary MR.

Figure 1.

The team responsible for the first MitraClip implantation in Portugal.

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Percutaneous valvuloplasty to treat MR is now a real solution for carefully selected patients who are considered inoperable or at high surgical risk. It requires allocation of significant resources, including the creation of multidisciplinary teams, but it is the only treatment option for a considerable number of patients. Percutaneous valve replacement may appear a simpler and more widely applicable solution, but it affects the subvalvular apparatus and ventricular geometry, increases the aggressiveness of the procedure and has all the limitations of implanting a biological valve in mitral position. I believe that the future will see the simultaneous development and growth of techniques of percutaneous repair, percutaneous valve replacement and minimally invasive surgery. Such diversity of therapeutic options will widen the range of candidates for treatment, all of which will have a role to play.