What is the most common etiology of aortic (aortic valve) stenosis in the United States?

From the Guidelines

The most common etiology of aortic stenosis in the United States is calcific degeneration of the aortic valve, particularly in older adults. This condition develops when calcium deposits form on the valve leaflets over time, causing them to become stiff and narrow, which restricts blood flow from the left ventricle to the aorta. Calcific aortic stenosis typically affects people over 65 years of age and its prevalence increases with advancing age. The process begins with lipid accumulation, inflammation, and calcification that progressively worsens over decades. Risk factors that accelerate this process include hypertension, diabetes, smoking, and elevated cholesterol levels. While congenital bicuspid aortic valve is the second most common cause of aortic stenosis in the US, affecting 1-2% of the population, calcific degeneration of trileaflet valves remains the predominant etiology in the general population, accounting for approximately 70-80% of cases in adults requiring aortic valve replacement, as supported by the most recent evidence 1.

Key Points

• Calcific aortic stenosis is the most common cause of valvular aortic stenosis in adults in the United States, as stated in 1 and further supported by 1 and 1.
• The condition is characterized by lipid accumulation, inflammation, fibrosis, and calcification of the aortic valve leaflets.
• Risk factors for calcific aortic stenosis include hypertension, diabetes, smoking, and elevated cholesterol levels.
• Calcific degeneration of trileaflet valves accounts for approximately 70-80% of cases in adults requiring aortic valve replacement, making it the predominant etiology in the general population, as indicated by 1.

Clinical Implications

The diagnosis and management of aortic stenosis are critical in preventing morbidity and mortality. Early detection and treatment of calcific aortic stenosis can significantly improve quality of life and reduce the risk of complications, such as heart failure, arrhythmias, and sudden cardiac death. Transcatheter aortic valve replacement (TAVR) has emerged as a viable treatment option for high-risk patients, as discussed in 1. Accurate imaging and annular sizing are essential for optimal device deployment and minimizing complications, highlighting the importance of pre-procedure screening and evaluation.

From the Research

Etiology of Aortic Valve Stenosis

• The most common etiology of acquired aortic valve stenosis is calcific (degenerative) aortic valve disease 2, 3, 4, 5, 6.
• Calcific aortic valve disease is characterized by a slowly progressive, asymptomatic period which can last decades 3.
• This disease process is not a passive degenerative process, but rather an active disease process with identifiable initiating factors, clinical and genetic risk factors, and cellular and molecular pathways that mediate disease progression 2, 4.

Pathophysiology and Risk Factors

• The early lesions of aortic valve sclerosis resemble arterial atherosclerotic plaques 2.
• Atherosclerotic risk factors and clinical atherosclerotic cardiovascular disease are independently associated with aortic sclerosis, suggesting that it represents an atherosclerosis-like process involving the aortic valve 2, 3, 4, 6.
• The pathophysiology of calcific aortic stenosis is similar to that of vascular atherosclerosis 4, 6.

Prevalence and Treatment

• Calcific aortic stenosis is the most common indication for surgical valve replacement in the United States 4, 5.
• The standard therapy for symptomatic patients with severe aortic stenosis is replacement of the valve 5.
• Medical therapies, such as statins, angiotensin-converting enzyme inhibitors, and biphosphanates, are being investigated to delay the progression of aortic stenosis 5.