What is the most common cause of aortic stenosis by age group in the United States (US)?

From the Guidelines

The most common cause of aortic stenosis varies by age group in the US, with congenital bicuspid aortic valve predominant in those under 30, bicuspid aortic valve disease and rheumatic heart disease common in middle-aged adults, and degenerative calcific aortic stenosis most common in elderly patients over 65 years. In patients under 30 years old, congenital bicuspid aortic valve is the predominant cause of aortic stenosis, as noted in studies such as 1. For middle-aged adults (30-65 years), bicuspid aortic valve disease remains common, but rheumatic heart disease can also be seen, as mentioned in 1. In elderly patients over 65 years, degenerative calcific aortic stenosis is by far the most common etiology, as stated in 1 and 1, with this age-related calcification occurring due to progressive calcium deposition on the valve leaflets over time, similar to atherosclerosis, and influenced by risk factors like hypertension, hyperlipidemia, diabetes, and smoking. Some key points to consider include:

• The calcification process gradually restricts valve opening, leading to obstruction of left ventricular outflow and the classic symptoms of angina, syncope, and heart failure when severe, as discussed in 1 and 1.
• Understanding these age-specific patterns helps clinicians appropriately evaluate and manage patients with suspected aortic stenosis, as emphasized in 1.
• The most recent guidelines, such as those from the European Society of Cardiology and the American College of Cardiology, provide recommendations for the management of severe aortic stenosis, including the use of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement, as noted in 1. Overall, the most common cause of aortic stenosis in the US varies by age group, with degenerative calcific aortic stenosis being the most common cause in elderly patients, as supported by the most recent evidence from 1 and 1.

From the Research

Aortic Stenosis Causes by Age Group

• The most common cause of acquired aortic stenosis is calcific degeneration, characterized by a slowly progressive, asymptomatic period which can last decades 2.
• A bicuspid aortic valve is the most common cause for AS until the seventh decade and calcific valve degeneration is responsible thereafter 3.
• In the US, calcific aortic stenosis affects 1% to 2% of adults older than 65 years and approximately 12% of adults older than 75 years 4.

Age-Related Prevalence of Aortic Stenosis

• Aortic stenosis is the most commonly encountered valvular disease in the elderly, with approximately 2-3% of individuals over 65 years of age afflicted 2.
• Severe aortic valve stenosis remains the main cause of morbidity and mortality in the elderly, reaching a prevalence of 2-7% above the age of 65 years old 5.
• The prevalence of calcific AS is age-dependent, and thus is expected to increase due to demographic aging of the global population 6.

Diagnostic Evaluation and Therapeutic Options

• Echocardiography can detect AS and measure the severity of aortic valve dysfunction 4.
• Valve replacement is based on surgical risk, valve durability/hemodynamics, need for anticoagulation and patient preferences 3.
• Transcatheter aortic valve implantation is an alternative in older patients at low, intermediate, high or prohibitive risk 3, 5.