After two years, intermediate-risk patients with severe symptomatic aortic stenosis had similar rates of all-cause mortality or disabling stroke whether they underwent transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR), according to a randomized trial.
A Bayesian analysis found that 12.6 percent of patients in the TAVR group and 14.0 percent in the surgery group had reached the primary endpoint, which was the composite of death from any cause or disabling stroke at 24 months.
Lead researcher Michael J. Reardon, MD, of Methodist DeBakey Heart and Vascular Center in Houston, presented the results in a late-breaking clinical trial session at the ACC scientific session on March 17 in Washington, D.C. The findings were simultaneously published online in The New England Journal of Medicine.
The patients underwent TAVR with Medtronic’ self-expanding CoreValve system or Evolut R system, both of which are FDA-approved for patients with severe aortic stenosis at high or extreme risk for surgery. Medtronic funded this study, which was known as SURTAVI.
The FDA has not approved the CoreValve and Evolut R systems for intermediate-risk patients. However, in 2016, Medtronic received a CE Mark for the systems in intermediate-risk severe aortic stenosis patients.
As of now, the Sapien 3 transcatheter heart valve (Edwards Lifesciences) is the only FDA-approved TAVR device for intermediate-risk patients.
Medtronic has submitted results of the SURTAVI trial to the FDA and hopes to expand the approval of the CoreValve and Evolut R for intermediate-risk patients.
“I personally expect very rapid approval because this data is really so outstanding,” Reardon said in an interview with Cardiovascular Business.
In the SURTAVI trial, the researchers enrolled 1,746 patients at 87 centers in the U.S., Europe and Canada from June 19, 2012, to June 30, 2016. Patients were randomized in a 1:1 ratio to undergo TAVR or SAVR. All of the patients had symptomatic, severe aortic stenosis and had intermediate surgical risk as determined by the heart team.
The researchers defined intermediate-risk as an estimated 3 percent to 15 percent risk of 30-day surgical death based on the Society of Thoracic Surgeons Predicted Risk of Mortality and nontraditional factors such as coexisting illnesses, frailty and disability.
At baseline, the mean age was 79.8 years old, and 56.8 percent of patients were males, In addition, 34.5 percent of patients had diabetes, 34.5 percent had chronic lung disease, 52.3 percent had a five-meter gait speed of more than six seconds and 12.2 percent had falls within the past six months.
Among the patients in the TAVR group, 83.9 percent were implanted with the CoreValve and the remaining 16.1 percent were implanted with the next-generation Evolut R, which the FDA approved in June 2015. The FDA expanded the approval of the Evolut R in October 2016.
At 24 months, the rate of death from any cause was 11.4 percent in the TAVR group and 11.6 percent in the surgery group, while the rate of disabling stroke was 2.6 percent and 4.5 percent, respectively. The 30-day all-cause mortality rates were 2.2 percent with TAVR and 1.7 percent with SAVR.
“This is the best two-year survival we’ve seen so far, and TAVR is still just as good as surgery,” Reardon said. “This gives you a lot of hope as you move into lower risk groups.”
The researchers also found that New York Heart Association symptoms and quality of life improved throughout the 24-month follow-up period. In addition, they mentioned surgery was associated with higher rates of acute kidney injury, atrial fibrillation and transfusion requirements, whereas patients in the TAVR group had higher rates of residual aortic regurgitation and need for pacemaker implantation. Further, they noted that TAVR was associated with better aortic valve hemodynamics.
The SURTAVI study had a few limitations, according to the researchers, including that a relatively high number of patients in the surgery group unexpectedly withdrew from the trial. They also mentioned that fewer than 20 percent of patients were implanted with the Evolut R. In addition, they said that they needed a longer follow-up period to compare TAVR and SAVR.
Previously, the PARTNER IIA trial found that intermediate-risk patients who received the Sapien TAVR valve (Edwards Lifesciences) had similar rates of death from any cause or disabling stroke compared with SAVR. During that study, the 24-month mortality rates were 16.7 percent with TAVR and 18 percent with SAVR, which the researchers said suggests patients in the SURTAVI trial were at a lower risk than those in the PARTNER IIA trial.
Reardon noted that current guidelines suggest TAVR is a reasonable alternative to SAVR for intermediate-risk patients, but that is only based on results of the PARTNER IIA trial.
“These are the kind of things that actually change the guidelines and make TAVR equivalent to surgery in this patient risk group,” Reardon said. “I think this trial will change the guidelines further because now having two randomized trials that met their primary endpoint, I expect the next version of the guidelines to make TAVR a Class I indication in intermediate-risk also.”