Transcatheter aortic valve implantation: current and future approaches

The first human transcatheter aortic valve implantation (TAVI) in 2002, and several subsequent single-center series, showed the feasibility of this new approach for the treatment of patients with severe aortic stenosis who were considered to be at very high or prohibitive surgical risk. More-recent multicenter registries have confirmed the safety and efficacy of this procedure, despite a very-high-risk patient profile. Moreover, the randomized, controlled PARTNER trial has confirmed both the superiority of TAVI over medical treatment in patients not considered to be candidates for standard surgical aortic valve replacement and the noninferiority of TAVI compared with surgical aortic valve replacement in high-risk patients. The hemodynamics of transcatheter valves are usually excellent, although residual paravalvular aortic regurgitation (usually trivial or mild) is frequent. Stroke, major vascular complications, and conduction disturbances leading to permanent pacemaker implantation remain among the most-concerning periprocedural complications of TAVI. Nevertheless, promising preliminary data exist for long-term outcomes following TAVI, 'valve-in-valve' TAVI for surgical prosthesis dysfunction, and for the treatment of lower-risk patients. Improvements in transcatheter valve technology, optimization of procedural and midterm results, and confirmation of long-term durability of transcatheter valve prostheses will determine the expansion of TAVI towards the treatment of a broader spectrum of patients.