Update on transcatheter aortic valve implantation.

Aortic stenosis affects a significant number of patients worldwide, and carries a dismal prognosis once symptoms develop. Unfortunately, a large number of patients present a prohibitive risk for surgical aortic valve replacement. Therefore, transcatheter aortic valve implantation has emerged as a promising technology for providing treatment to this group of patients. Currently available valves include the balloon-expandable Edwards SAPIEN valve (Edwards Lifesciences, Irvine, CA), which is usually implanted via a transfemoral or transapical approach, and the self-expanding CoreValve ReValving system (Medtronic, Minneapolis, MN), which uses only the transfemoral route. Early experience with the procedure performed on a compassionate-use basis was encouraging, and led to a number of first-in-man and feasibility studies. These trials demonstrated the safety and efficacy of valve implantation and led to CE (European Conformity) mark approval of both valves in Europe. Use of the SAPIEN valve in the United States is limited to the recently completed PARTNER (Placement of Aortic Transcatheter Valve) randomized trial comparing transcatheter and surgical aortic valve replacement in high-risk patients, and its post-trial registry. The CoreValve is not yet available in the United States. With improved device technology, better understanding of patient selection and pre- and periprocedural imaging, and greater procedural experience, widespread diffusion of transcatheter aortic valve implantation is expected.