TOPLINE:

Higher midwall fibrosis burden was associated with a greater risk for adverse outcomes including hospitalization for unplanned aortic stenosis in asymptomatic patients with severe aortic stenosis. However, the benefits of early intervention were similar among patients with high or low fibrosis burden.

METHODOLOGY:

• Researchers conducted a post hoc analysis of a trial conducted between August 2017 and October 2022 at 24 cardiac centers across the UK and Australia to examine whether asymptomatic patients with greater midwall fibrosis experienced more adverse events.
• A total of 224 asymptomatic participants with severe aortic stenosis (mean age, 73 years; 28% women), including those with both high and low midwall fibrosis burden (n = 112 in each group), were followed up for a median of 42 months.
• The patients were randomly assigned to receive either early intervention with transcatheter or surgical aortic valve replacement or guideline-directed conservative management.
• The primary endpoint was a composite of all-cause mortality or hospitalization due to an unplanned aortic stenosis-related event, defined as any unplanned admission with syncope, heart failure, chest pain, ventricular arrhythmia, or second- or third-degree heart block attributed to aortic valve disease.
• Cardiac MRI was used to observe midwall late gadolinium enhancement and identify regions of noninfarct replacement fibrosis.

TAKEAWAY:

• Overall, 26% of patients with high fibrosis burden above the median compared with 14% with low fibrosis burden below the median experienced the composite primary endpoint (hazard ratio [HR], 1.86; 95% CI, 1.20-3.50).
• Each 1% rise in midwall fibrosis burden was associated with a 23% increased risk for the primary composite endpoint (HR, 1.23; 95% CI, 1.08-1.37) and a 22% higher risk for unplanned aortic stenosis-related hospitalizations (HR, 1.22; 95% CI, 1.03-1.40).
• In patients with high midwall fibrosis burden, early intervention was associated with a lower risk for unplanned aortic stenosis-related hospitalization than conservative management (HR, 0.27; 95% CI, 0.08-0.77), but no difference was observed in all-cause mortality.
• In patients with low fibrosis burden below the median, no differences were noted in the primary endpoint or its components between the early intervention and conservative management groups.

IN PRACTICE:

“Our data indicate that patients with more advanced replacement fibrosis have at least as much to gain from early intervention as those with a low burden of fibrosis,” the authors of the study wrote. 

SOURCE:

The study was led by Neil J. Craig, PhD, University of Edinburgh in Scotland. It was published online on April 15 in JAMA Cardiology.

LIMITATIONS:

The trial had a modest sample size that reduced statistical power to assess potential interaction effects between randomization arms and fibrosis burden. The median time to early intervention was 5 months, which could have been too long and may have impaired the ability to identify a potential benefit. 

DISCLOSURES:

The trial was funded by The Sir Jules Thorne Charitable Trust. Several authors reported receiving funding, grants, personal, consulting, or speaker fees, shareholding, travel and accommodation support, as well as nonfinancial support, from various institutions and pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.