Bicuspid aortic stenosis epidemiology and demographics

Overview
In this condition, instead of three valve cusps, the aortic valve has two cusps which results from the fusing of one of the commissures. Bicuspid aortic stenosis is the most common congenital abnormality of the heart accounting for 5% of congenital heart defects and it occurs in 1-2% of the population. It can be manifested as a murmur and usually has no long term health consequences, but if it does, the manifestation of aortic stenosis occurs 10 years earlier.

Genetics
Bicuspid aortic valve has been found to be an inheritable condition, with a demonstrated association with Notch 1. Familial clustering as well as isolated valve defects have been documented. The incidence of bicuspid aortic valve can be as high as 10% to 20% in families affected with the valve problem. Other congential heart defects are associated with bicuspid aortic valve at various frequencies.

Timing of Diagnosis
This condition is often undiagnosed until later in life when the person develops symptomatic aortic stenosis. Aortic stenosis occurs in this condition usually in patients in their 40s or 50s, an average of 10 years earlier than can occur in people with congenitally normal aortic valves. 30% of cases are diagnosed in adolescence.

Incidence of Bicuspid Aortic Valve Disease Versus Degenerative Disease Among Patients with Surgical AS
The congenital bicuspid aortic valve may become calcified, which may lead to half the cases of surgically important pure aortic stenosis in adults, with varying degrees of severity of aortic stenosis and aortic regurgitation.

Male Predominance
Bicuspid aortic stenosis is more common in men than women (3:1 to 5:1).