Transcatheter aortic valve replacement (TAVR) continued to hold its own against surgery in low-risk patients with severe aortic stenosis, based on two-year results presented May 19 at EuroPCR in Paris.
“From what I can see from the NOTION data, at least in selective, low-risk patients, you can use TAVR instead of SAVR,” Lars Sondergaard, MD, DMSc, told Cardiovascular Business. He presented the two-year data on behalf of the NOTION (Nordic Aortic Valve Intervention Trial) investigators. “But if you want to introduce it as a routine treatment in younger patients, then you need more long-term data.”
The NOTION study is an investigator-initiated all-comers clinical trial that randomized 280 patients to be implanted with the CoreValve TAVR device (Medtronic) or undergo surgical aortic valve replacement (SAVR). The trial enrolled patients between 2009 and 2013 from two sites in Denmark and one in Sweden who were 70 years or older and who were candidates for SAVR and TAVR with no limitations on their predicted risk. As a result, 81.8 percent of the study cohort was considered low risk.
The primary outcome was the composite of all-cause death, stroke or MI after the procedure. At one year, in an as-treated analysis the primary outcome occurred in 11.3 percent of the TAVR patients and 15.7 percent of the SAVR patients. At two years, the rates were 15.8 percent and 18.8 percent, respectively. The rate of death from any cause was 8 percent and 9.8 percent, respectively.
The trial was designed as a superiority study but the findings did not reach statistical significance. A post-hoc analysis showed TAVR to be noninferior to SAVR.
Patients in the TAVR group had a higher rate of needing a permanent pacemaker at one and two years compared with SAVR (one year: 38 percent vs. 2.4 percent; two years: 41.3 percent vs. 4.2 percent) but TAVR had a lower rate of new onset or worsening atrial fibrillation (one year: 21.2 percent vs. 59.4 percent; two years: 22.7 percent vs. 60.2 percent). TAVR also had a higher rate of moderate to severe aortic valve regurgitation compared with SAVR, which persisted at two years.
The NOTION trial used first-generation devices and relied on 2D transesophageal echocardiography for sizing, which was the standard protocol when the trial started. Sondergaard, who is a cardiologist with Rigshospitalet-Copenhagen University Hospital in Denmark, pointed out that the use of newer devices and a shift toward CT scanning have led to better pacemaker and regurgitation outcomes.
“I am sure we can do better than we did at that time using [2D transesophageal echocardiography] for sizing and also the first-generation valves,” he said.
Durability of TAVR valves will need to be established if the less invasive approach is used in younger patients, Sondergaard said. Pivotal trials that have led to the approval of TAVR devices in the U.S. enrolled inoperable and then high-risk patients, with participants in the middle 80s. The mean age in NOTION was 79.1 years.
Although it was randomized, NOTION was relatively small and was limited to one region. Sondergaard said it likely will be used to help design larger TAVR clinical trials in low-risk patients.