Transcatheter aortic valve replacement: current developments, ongoing issues, future outlook.

Since the first clinical implantation in 2002, transcatheter aortic valve implantation or transcatheter aortic valve replacement (TAVR) has become an established therapy in the treatment of symptomatic severe aortic stenosis in patients deemed too high risk for surgical aortic valve replacement. With over 50,000 implants performed in more than 40 countries, a large amount of clinical data have emerged in this rapidly growing field. Careful patient selection, systematic risk stratification, optimal valve sizing, meticulous procedural techniques, and complications management are all important elements to achieve good outcomes. However, several critical issues exist with TAVR that need to be addressed before it can become more widely adopted. Quality of life improvement and cost-effectiveness of TAVR, when compared to surgical aortic valve replacement, remain uncertain in lower risk patients. Stroke, paravalvular leak, vascular complication, bleeding, and heart block represent only a few of the key concerns in this therapy. Valve-in-valve procedures are becoming a novel application of transcatheter heart valve in the treatment of a degenerated bioprosthesis, and next generation heart valves that address some of these ongoing issues are currently under evaluation. Future prospective studies will allow us to refine this therapy and optimize outcomes in this high-risk patient population.