Challenges for Expanded Use of Transcatheter Aortic Valve Replacement
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Since its development >15 years ago, transcatheter aortic valve replacement (TAVR) has rapidly evolved and is now a well-established treatment option for patients with severe symptomatic aortic stenosis at increased risk for surgical aortic valve replacement (SAVR). In patients with a prohibitive risk for open-heart surgery, TAVR reduced the 1- and 2-year all-cause mortality by almost half compared with standard medical therapy.1 TAVR with a balloon-expandable prosthesis in high-risk patients achieved similar 5-year rates of cardiovascular outcomes and mortality compared with SAVR.2 At 3 years, TAVR with a self-expanding prosthesis reduced the incidence of stroke and provided similar survival outcomes compared with surgery in high-risk patients.3 Most recently, TAVR achieved almost identical rates of the composite of all-cause death and disabling stroke compared with surgery for patients at intermediate surgical risk.4,5 Consequently, guidelines now include TAVR as a treatment option for extreme-, high-, and intermediate-risk patients with severe symptomatic aortic stenosis.6 The number of patients treated with commercial TAVR in the United States has nearly doubled from >26 000 in 20147 to >50 000 in 2016 and has already reached >300 000 treated patients worldwide. However, several challenges need to be resolved for TAVR to become the mainstream treatment for patients with aortic stenosis.
Low-Risk Patients and Valve Durability
TAVR is currently being examined as a therapeutic option for low-risk patients in 2 large multicenter randomized controlled trials (PARTNER [The Placement of Aortic Transcatheter Valve Trial] III and The CoreValve low-risk trial). Preliminary signals from the NOTION (Nordic Aortic Valve Intervention) trial are encouraging finding no significant difference in the 30-day and the 1-year rates of stroke and all-cause mortality in low-risk patients randomized to SAVR or TAVR with the CoreValve self-expanding prosthesis.8 These reported outcomes are similar to those of low-risk patients who underwent SAVR in a contemporary …