Moderate aortic stenosis linked to a significant risk of death—should earlier interventions be considered?
Moderate aortic stenosis (AS) is associated with a heightened mortality risk, according to a new meta-analysis published in JACC: Cardiovascular Interventions.[1] While this might suggest some moderate AS patients should undergo earlier interventions, the study’s authors noted that additional research is still needed.
“Although the impact of severe AS on clinical outcomes has been extensively reported in the literature, conflicting data exist about the clinical course of patients with lower grades of stenosis,” wrote first author Augustin Coisne, MD, PhD, of the Montefiore-Einstein Center for Heart and Vascular Care, and colleagues. “Given the growing interest in intervention in moderate AS patients, a deeper understanding of the population risk profile and clinical course of the disease may serve as a benchmark for future clinical studies.”
The team’s primary meta-analysis included data from more than 12,000 moderate AS patients who originally participated in one of 25 different studies. The mean follow-up period was 3.7 years. Most of the included studies relied on echocardiography to evaluate each patient, but three older studies used heart catheterization. Another meta-analysis of more than 277,000 patients from eight different studies compared mild AS with moderate AS. A third meta-analysis of more than 13,000 patients from 11 different studies compared moderate AS with severe AS.
Overall, moderate AS was linked with an all-cause mortality rate of 9 per 100 person-years. The rates of cardiac death, heart failure and sudden death were 4.9, 3.9 and 1.1 per 100 person-years, respectively. Moderate AS patients presenting with diabetes, coronary artery disease, left ventricle dysfunction and AS-related symptoms all faced a greater risk of all-cause mortality.
As one might expect, each grade of AS severity was associated with an increased mortality risk. Patients with mild or no AS faced the lowest risk, patients with moderate AS faced a higher risk, and patients with severe AS faced the highest risk.
The authors also noted that the rate of moderate AS patients who went on to undergo aortic valve replacement within the follow-up period was 7.2 per 100 person-years.
“The most likely explanation for this finding is the progression of symptoms or stenosis severity,” Coisne et al. wrote. “It was recently described that more than one-third of patients with moderate AS progress to severe AS in a time frame of ∼2.1 years, and this progression is associated with a higher risk of cardiac events.”
The team highlighted the importance of this finding, noting that it supports the need for “frequent re-evaluations” of patients presenting with moderate AS.
When reviewing these findings, one key question still remains: Does this increased mortality risk mean more patients with moderate AS should be undergoing interventions such as transcatheter aortic valve replacement (TAVR)?
The authors called for additional research—specifically in the form of randomized controlled trials—to explore this issue in detail.
“The impact of early intervention in moderate AS patients having high-risk features deserves further investigation,” they wrote.