Patients with moderate aortic stenosis (AS) face a much higher risk of death than those with mild or no AS, according to a new meta-analysis published in the Journal of the American Heart Association.[1] Should they be considered for transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR)?
The study’s authors noted that American College of Cardiology/American Heart Association guidelines and European Society of Cardiology/European Association by Cardio-Thoracic Surgery guidelines both recommend aortic valve replacement (AVR) in patients with severe symptomatic AS or asymptomatic patients with a significantly reduced left ventricular ejection fraction (LVEF). Among patients with moderate AS, meanwhile, the guidelines recommend a “watching waiting approach” anchored by regular echocardiograms.
“The rationale behind the contrasting recommendations concerning the timing of intervention in AS remains a matter of discussion,” wrote first author Xander Jacquemyn, BSc, a researcher with KU Leuven in Belgium and the Johns Hopkins School of Medicine in Baltimore, and colleagues. “Recent large‐scale observational studies found the prognosis of patients with moderate AS may be more unfavorable than previously thought, particularly when concurrent systolic dysfunction is present.”
To gain a better understanding of the potential risks associated with moderate AS, Jacquemyn et al. examined data from more than 409,000 patients who originally participated in one of ten different studies. Out of that large group of patients, 2.8% presented with moderate AS. The remaining patients all presented with mild or no AS. The median follow-up period was 3.8 years. Patients with moderate AS tended to be older than the patients with mild or no AS. They were also more likely to present with hypertension or coronary artery disease.
Overall, the 15-year survival rates were 23.3% for patients with moderate AS and 58.9% for patients with mild or no AS. This increased risk was still present when adjusting for baseline patient characteristics such as age, sex and LVEF.
The authors also performed a second analysis that focused on patients with heart failure with reduced ejection fraction (HFrEF). Among that group, 10-year survival was 15.5% for patients with moderate AS and 37.3% for patients with mild or no AS.
“The increased mortality rates in patients diagnosed with moderate AS have significant clinical implications,” the authors wrote. “The cornerstone of clinical management for moderate AS, as widely advocated by current guidelines, is the ‘watchful waiting’ approach. Our findings raise questions about whether the current risk of not proactively treating moderate AS outweighs the potential benefits of AVR and suggest the possibility of a paradigm shift favoring earlier intervention.”
The group also noted that multiple randomized trials are currently examining the potential benefits of preemptive AVR in patients with moderate AS. If those trials do reveal a significant benefit, they explained, SAVR “might be deemed a better option” than TAVR when treating younger patients due to the “high likelihood of outliving the first implanted valve.”
Much more research is required, however, before recommendations can be made in either direction.
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Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.