Transcatheter aortic valve replacement in intermediate and low risk patients-clinical evidence
The encouraging results of the PARTNER 2 (Placement of AoRtic TraNscathetER Valves 2) trial led to the approval of transcatheter aortic valve replacement (TAVR) in intermediate-surgical-risk patients. Recently, the SURTAVI (SUrgical Replacement and Transcatheter Aortic Valve Implantation) investigators demonstrated the feasibility of TAVR with self-expanding valves in intermediate-risk patients. The focus has now shifted to clinical trials comparing TAVR to surgery in low-surgical-risk populations with a goal to expand TAVR to all-risk patients. However, the low-surgical-risk patients continue to be acceptable candidates for surgical aortic valve replacement, with proven outcomes over many decades. Although new data has emerged showing feasibility of TAVR in young patients with bicuspid valves, with newer generation TAVR valves there will be minimal tolerance for adverse outcomes in the low risk category. To expand the reach of TAVR into low-surgical-risk patients, important questions about valve durability, leaflet thrombosis, higher rates of paravalvular leak and permanent pacemakers (PPM) will need to be addressed. However, as TAVR technology continues to evolve, it seems to be just a matter of time before TAVR establishes itself as a modality for aortic valve replacement regardless of surgical risk.