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Percutaneous catheter based edge-to-edge mitral valve (MV) repair with a mitral clip (MitraClip, Abbott Vascular, Abbott Park, Illinois, USA) mimics Alfieri's surgical technique, bringing the anterior and posterior leaflets together from beneath the valve with a metallic stitch (clip). The procedure creates a ‘double orifice’ repair, re-establishing leaflet coaptation and thereby reducing mitral regurgitation (MR).
In 2005, Feldman et al published their initial feasibility data (EVEREST (Endovascular Valve Edge-to-Edge Repair) phase 1 clinical trial) of a cohort of 27 patients with moderate-to-severe MR who were symptomatic or asymptomatic with compromised left ventricular (LV) function.1 Patients were selected on the basis of specific valve morphology for which the procedure was thought to be particularly suited. In the case of degenerative MV regurgitation (ie, flail leaflet), anatomical inclusion criteria were a regurgitant jet originating from the A2/P2 segment with a flail gap of <10 mm and a flail width of <15 mm. In the case of functional MV regurgitation, inclusion criteria were a coaptation length of at least 2 mm and a coaptation depth of no more than 11 mm.1 Post-procedural success (ie, residual MR ≤2+ on a scale of 4+) was achieved in 74% of cases with <1% in-hospital mortality. At 1 year, freedom from death, surgery or residual MR ≥2+ was 66%. The EVEREST II trial was presented for the first time at the 2011 American College of Cardiology Scientific Session /i2 summit and subsequently published.2 The conclusions of this second trial was that the MitraClip, though less effective at reducing MR (a threefold greater percentage of percutaneously treated patients had ≥2+ MV regurgitation compared with surgically treated patients), was not inferior to surgical repair or replacement, with a significantly reduced adverse event rate.2 It is important to note that in the case of failure, the surgical option always remains open.