Why is the study important?

The prospect of earlier intervention in patients with asymptomatic severe aortic stenosis (AS) in an attempt to limit cardiac damage and improve outcomes remains an area of interest as transcatheter aortic valve replacement (TAVR) outcomes continue to improve. The purpose of the EVOLVED study was to compare all-cause deaths or unplanned AS–related hospitalizations using guideline-directed medical management and surveillance vs. either surgical aortic valve replacement (SAVR) or TAVR in patients with asymptomatic severe AS and evidence of myocardial fibrosis on cardiac magnetic resonance (CMR) imaging.

Should I change my practice because of these findings?

The study did not demonstrate a clear benefit of early SAVR/TAVR in patients with asymptomatic severe AS and evidence of myocardial fibrosis on CMR. This was in part due to the limited power of the study, having enrolled a total of 226 patients. Additional data will be needed to further understand which subsets of asymptomatic patients might benefit most from early intervention with either TAVR or SAVR.

What question was the study supposed to answer?

This study sought to answer the question of whether or not early intervention in patients with asymptomatic severe AS and myocardial fibrosis on CMR would benefit from early intervention with either SAVR or TAVR compared to conservative management alone.

What did the study show?

A total of 226 subjects with asymptomatic severe AS and myocardial fibrosis on CMR were enrolled in this multicenter, randomized controlled trial which compared conservative management and surveillance to early intervention with either SAVR or TAVR. The mean age of subjects enrolled was 73, with just 28% of subjects being female. There were no differences in their primary composite outcome of all-cause death or unplanned AS–related hospitalizations between both cohorts (23% vs. 18%, p=0.44). Early intervention was found to result in a lower 12-month rate of New York Heart Association Class II-IV symptoms than conservative management alone (19.7% vs. 37.9%, odds ratio, 0.37 [95% confidence interval, 0.20-0.70]).

How good was the approach/methodology?

The EVOLVED study was a modestly-sized multicenter randomized controlled trial that did not demonstrate an appreciable effect on all-cause death or unplanned aortic stenosis–related hospitalization. The primary composite outcome demonstrated a wide 95% confidence interval, underscoring the need for additional data to help elucidate any potential benefit of early intervention in patients with asymptomatic severe AS and evidence of myocardial fibrosis on CMR.