The supra-annular self-expanding Evolut PRO/PRO+/FX TAVR device was found to be superior for valve function and noninferior for clinical outcomes at one year compared to the balloon-expandable SAPIEN 3/3 Ultra TAVR device, according to the results of the SMART trial, presented during a Late-Breaking Clinical Trial Session at ACC.24 and published simultaneously in the New England Journal of Medicine.

The trial, conducted at 83 international sites across North America, Europe and the Middle East, randomly assigned 716 patients (mean age 80 years, 87% women) who underwent TAVR and had a valve annulus ≤430 mm² to either the self-expanding Evolut valve or the balloon-expandable SAPIEN valve. Participants were considered to face a low to intermediate risk, with a mean Society of Thoracic Surgeons Predicted Risk of Mortality of 3.3%.

Results at one year showed that there was no significant between-group difference in the primary composite endpoint of death, disabling stroke or rehospitalization for heart failure – which occurred in 9.4% of patients who received the Evolut valve and 10.6% of those receiving the SAPIEN valve (p<0.001). For the co-primary endpoint of valve function, defined in terms of a composite of structural and nonstructural valve deterioration, blood clotting around the valve, infection of the valve and aortic valve reintervention, the Evolut device was found to be superior; the endpoint occurred in 9.4% of patients who received the Evolut valve and 41.6% of those receiving the SAPIEN valve (p<0.001).

All prespecified secondary endpoints were statistically significant in favor of the self-expanding valve, including blood pressure across the valve and the size of the valve opening. The aortic valve mean gradient at 12 months was 7.7 mm Hg with the self-expanding valve and 15.7 mm Hg with the balloon-expandable valve.

"Clinically, at one year, either valve is reasonable, and the results are pretty similar, although mild valve leaks and some measures of quality of life were better with Evolut," said Howard C. Herrmann, MD, FACC, lead author of the study. "Furthermore, this is the first time we get to identify differences between the devices that might impact later patient outcomes."

Similar results were seen across all subgroups, although the researchers plan to analyze additional subgroups to determine whether valve performance or clinical outcomes may vary among people in different age groups or among people with different comorbidities or annulus size. They also plan to assess measures of valve durability over time, which Herrmann said is becoming more important as younger patients are increasingly undergoing TAVR. Researchers will continue to track outcomes over the next five years.

This was the first trial to focus specifically on informing device selection for patients with small aortic annuli, a patient group that is primarily women and has been underrepresented in previous clinical trials for TAVR. "We think it's important to study this population, which represents up to 40% of all patients getting TAVR, and it's important to study women, who make up the majority of the small annulus population," said Herrmann.