Which of the following are the most common causes of aortic stenosis?

The most common causes of aortic stenosis primarily include age-related calcification and congenital structural abnormalities rather than inflammatory processes like rheumatic fever. While rheumatic fever can lead to valvular heart diseases, its role in aortic stenosis specifically is less significant in contemporary cases compared to the predominant causes.

Calcification of leaflets occurs with age, especially in patients over 70, as the aortic valve leaflets become calcified and stiff, leading to narrowing and obstruction of blood flow from the heart. This is often seen in individuals with risk factors such as hypertension and hyperlipidemia.

A congenital bicuspid valve is another leading cause, occurring when the aortic valve has only two cusps instead of the usual three. This structural anomaly predisposes individuals to premature calcification and stenosis.

In summary, while rheumatic fever can damage heart valves, it is more classical for mitral valve issues. In contrast, calcification of leaflets, particularly in older adults, and congenital conditions such as a bicuspid aortic valve are the primary causes of aortic stenosis in the general population today. Thus, the focus should be on these factors when considering the etiology of aortic stenosis.