Definition, Incidence and Prevalence of Aortic Stenosis

Definition of aortic stenosis

• Aortic stenosis (AS) is also called as aortic valve stenosis
• AS happens when has become narrow or constricted (stenotic) and does not open fully thus restricting blood flow
• Aortic valve is located between the left ventricle and aorta
• The left ventricle pumps oxygen rich blood out of the heart to the aorta through aortic valve
• When aortic valce becomes stenotic, the ability of left ventricle to pump out from heart to aorta is impaired
• As a result, organs receive an insufficient supply of oxygen rich blood (heart failure), and blood may back up into the lungs causing SOB

Incidence and Prevalence

1. in US…
• Aortic sclerosis increases in incidence with age and is present in:
• 29% of individuals older than 65 years and in
• 37% of individuals older than 75 years

• Patients with severe AS may be asymptomatic for many years despite the presence of severe LV outflow tract obstruction
• Such patients have a survival similar to those without aortic stenosis
• With the appearance of symptoms, however, their survival is reduced:

Symptoms ....................Survival Rate
Angina .......................4.5 years
Syncope/dizziness............2.6 years
Congestive heart failure.....1 year

2. Mortality/Morbidity Rate

Symptomatic Patients (moderate AS)

Mortality rates are around 25% at 1 yr & 50% at 2 years
More than 50% of deaths are sudden

Asymptomatic Patients(critical AS)

Excellent prognosis regarding survival with death rate less than 1% in a year
Only 4% of sudden cardiac death in severe aortic stenosis

3. In Western populations,

Aortic sclerosis................Aortic stenosis
25% over 65.....................3 % over 75

Around 16% of patients progress to stenosis in 7 yrs

4. Incidence of MI,

DISORDER............................................INCIDENCE OF MI
Septuagenarians with normal aortic valve.........6% over 5 years
Aortic scelerosis....................................8.6%
Aortic stenosis......................................11.3%

5. As our population ages, the prevalence of aortic stenosis inevitably rises.
• By 2020, about 3.5 million of a total population of 54 million in England can be expected to have aortic sclerosis and
• 150 000 to have severe aortic stenosis