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 68 ± 10 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 cm2 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. © 2015 Wiley Periodicals, Inc.