Expanding the indications for transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has revolutionized the treatment of symptomatic severe aortic valve stenosis. Current guidelines recommend TAVI in patients at increased operative risk of death. Advanced imaging planning, new transcatheter valve platforms, procedure streamlining and growing operator experience have improved procedural safety and bioprosthetic valve performance. As a result, TAVI has been explored for other indications. Two randomized trials published in 2019 to assess TAVI in patients with symptomatic severe aortic stenosis at low operative risk have set the stage for a new wave of indications. In younger and low-risk patients, TAVI had an early safety benefit over surgical aortic valve replacement and was associated with faster discharge from hospital and recovery and fewer rehospitalizations. In patients with symptomatic severe aortic stenosis, TAVI has now been explored across the entire spectrum of operative risk, from inoperable to low-risk populations, in properly designed, randomized clinical trials, although data on the long-term durability of these valves are lacking. The use of TAVI in severe bicuspid aortic valve stenosis, asymptomatic severe aortic stenosis, moderate aortic stenosis in combination with heart failure with reduced ejection fraction, and isolated pure aortic regurgitation is now under investigation in clinical trials. In this Review, we provide our perspective on these evolving indications for TAVI, discuss relevant available data from clinical trials, and highlight procedural implications and caveats of new and future indications. This Review discusses the evolving indications of transcatheter aortic valve implantation (TAVI), including the latest clinical trials in young and low-risk patients with symptomatic severe aortic stenosis and ongoing studies exploring TAVI for other indications, including severe bicuspid aortic valve stenosis and pure native aortic regurgitation, highlighting procedural implications and caveats of new and future indications. Key points Transcatheter aortic valve implantation (TAVI) is an accepted treatment option for elderly patients with symptomatic severe degenerative tricuspid aortic valve stenosis across the entire spectrum of operative risk. Long-term durability of transcatheter valves is unknown and requires further research. The use of TAVI with new-generation devices seems attractive for bicuspid aortic valve stenosis, but sizing algorithms might need to be modifi