Percutaneous Transcatheter Aortic Valve Implantation — The Evolution, Current Status and the Future

Aortic valve stenosis (AS) will become more common as the population ages. Once symptoms occur, the prognosis is poor. Aortic valve replacement (AVR) has been the standard of care, improving symptoms and prolonging survival. A significant proportion of patients, however, do not undergo AVR due to increased surgical-risk. The technology of transcatheter aortic valve implantation (TAVI) emerged in 2002 and offered some of these patients an alternative therapy. A randomised (PARTNER) trial has shown that TAVI (using the Edwards-Sapien transcatheter heart valve) was superior to medical therapy (including balloon aortic valvuloplasty) in inoperable patients with a significant reduction in all-cause mortality at one year. For high surgical-risk patients, TAVI demonstrated non-inferiority to open AVR, with similar all-cause mortality at one year. Currently two devices, the Edwards-Sapien and the CoreValve transcatheter heart valves, are in clinical use and are undergoing further trials. Device improvements will be required to enhance procedural success and safety and longer term data would be required to understand the longevity of these valves. Further trial data would be required to compare TAVI and open AVR in moderate surgical-risk patients if this technology were to become a more common therapy.