Percutaneous Repair or Surgery for Mitral Regurgitation EVEREST II Objective: to compare the efficacy of percutaneous implantation of a clip and conventional surgery for repair or replacement of the mitral valve Study: multicenter randomized controlled trial (2:1 ratio) Population: patients with grade 3+ or 4+ mitral regurgitation Endpoint: efficacy: freedom from death, surgery for mitral dysf. at 12 months safety: composite of MACE within 30 days