Transcatheter mitral valve implantation for inoperable severely calcified native mitral valve disease: A systematic review

Background: Transcatheter mitral valve implantation (TMVI) for severely calcified native mitral valve disease recently emerged as a treatment option in patients deemed inoperable by conventional techniques. Yet no systematic appraisal currently exists characterizing this novel treatment paradigm. Methods: A systematic literature review summarizing the clinical, anatomical, peri- and post-procedural characteristics underscoring the technical feasibility of this procedure was performed. Results: Nine publications describing 11 patients [mean age 6810 years, 82% female, 82% severe mitral stenosis (MS), 18% severe mitral regurgitation (MR)] were identified. Mean STS score, trans-mitral gradient and effective orifice area were 10.5 +/- 4.6%, 12 +/- 2.4 mm Hg and 0.93 +/- 0.06 cm(2) respectively. All patients had severe, circumferential mitral annular calcification on imaging. Dedicated balloon-expanding transcatheter aortic valves were used in 10/11 cases, with 8/11 cases involving a true percutaneous approach with peri-procedural 3D trans-esophageal echocardiographic guidance; 3/11 cases involved an open left atrial approach. Following initial balloon inflation and valve deployment, procedural success rate was 73%, without residual paravalvular leaks (PVL). Successful immediate re-deployment of a 2nd valve was needed in 2 instances following significant PVL detection. Residual trans-valvular gradients ranged from 3 to 7 mm Hg, with no patient demonstrating >grade 2 MR. All patients survived the procedure, with 2 reported deaths on days 10- and 41 post-TMVI being non-cardiac-related. Mid-term clinical follow-up, reported in 8 patients, revealed 6 patients to be alive at 3-months with much improved functional status. Conclusions: TMVI for native severely calcified mitral valve disease appears technically feasible with acceptable initial acute and mid-term hemodynamic and clinical outcomes. The outcomes of an ongoing, dedicated global Sapien TMVI registry will shed further light on this evolving treatment paradigm. (c) 2015 Wiley Periodicals, Inc.