CHICAGO – After one year, intermediate-risk patients with severe aortic stenosis who underwent transcatheter aortic valve replacement (TAVR) with the Sapien 3 valve had better outcomes than a group that had surgical valve replacement, according to an observational study.
A propensity score analysis found that patients who received the Sapien 3 had lower rates of death, strokes and the composite endpoint of death, strokes and moderate to severe aortic regurgitation.
Lead researcher Vinod H. Thourani, MD, professor of surgery and medicine at the Emory School University of Medicine in Atlanta, presented the results during a late-breaking session at the ACC scientific session on April 3. The findings were simultaneously published online in The Lancet.
The FDA approved the Sapien 3 system (Edwards Lifesciences) in June 2015 to treat high-risk patients with severe aortic stenosis.
“This study shows the lowest mortality rate ever of any transcatheter valve platform after one year, which is very exciting for the management of aortic stenosis,” Thourani said in a news release. “A previous analysis by our team showed that almost 20 percent of all patients undergoing surgical aortic valve replacement in the United States are in the intermediate-risk category, so I believe that this could have a major impact on the treatment options we have available for many of these patients.”
For this analysis, the researchers analyzed 1,077 patients from 51 sites in the U.S. and Canada who enrolled in the PARTNER 2A Sapien 3 intermediate risk observational study. They then compared those patients with patients who enrolled in the PARTNER 2A randomized trial and were assigned to undergo surgical valve replacement.
Both prospective, multicenter studies included patients with symptomatic severe aortic stenosis who were at an intermediate risk of 30-day surgical mortality. Patients were excluded if they had a congenitally bicuspid aortic valve, severe aortic regurgitation, left ventricular ejection fraction lower than 20 percent, severe renal insufficiency and an estimated life expectancy of less than two years.
Cardiac surgeons and other heart team members assessed patients and considered them as intermediate risk if their Society of Thoracic Surgeons (STS) score was 4 percent or higher. Patients were also considered intermediate risk if their STS score was less than 4 percent, but they had liver disease, frailty, pulmonary hypertension and other risk factors that were not included in the score.
At baseline, the mean age was approximately 81 years old, and approximately 60 percent of patients were males. To account for differences in baseline characteristics between the two trials, the researchers used a prespecified propensity score analysis.
After a year, 7.4 percent of patients who received the Sapien 3 valve had died, 2 percent had disabling strokes, 1 percent had aortic valve re-intervention and 2 percent had moderate or severe paravalvular regurgitation.
The one-year all-cause mortality rates were 7.4 percent in the Sapien 3 group and 13.0 percent in the surgery group, while the one-year all-stroke rates were 4.6 percent and 8.2 percent, respectively.
For the propensity-score analysis, fewer patients in the Sapien 3 group had the primary composite endpoint of mortality, strokes and moderate to severe aortic regurgitation compared with the surgical valve replacement group. The Sapien 3 group also had fewer deaths and stroke, while the surgical valve replacement group had fewer instances of moderate or severe aortic regurgitation.
The researchers cited a few limitations of the study, including that the propensity score analysis was not the same as a randomized trial and may not have included relevant confounders that could influence the results. They also mentioned the study only examined intermediate-risk patients, although most patients were elderly and had several coexisting illnesses. They wrote that randomized trials comparing TAVR and surgery in younger, lower-risk patients without major comorbidities were needed.
Further, they noted that TAVR systems differ, so these results with the Sapien 3 valve may not be generalizable to other TAVR systems.