Medically reviewed by Dr Nabila Laskar, Consultant Cardiologist (GMC 7040901). Aortic stenosis is a narrowing of the aortic valve — the main outlet valve of the heart — that restricts blood flow from the heart to the body. It is the most common serious valve condition in adults and becomes increasingly prevalent with age.
In adults over 65, the most common cause is age-related calcification — calcium deposits accumulating on the valve leaflets, progressively stiffening and narrowing the valve opening over years. A bicuspid aortic valve (a congenital abnormality where the valve has two leaflets instead of three) causes stenosis to develop earlier, typically in the 40s–60s. Rheumatic heart disease is a less common cause in the UK today.
Aortic stenosis is often silent in mild and moderate stages. The appearance of symptoms — breathlessness on exertion, chest pain (angina), or fainting — marks a significant clinical turning point. Once symptomatic, the condition tends to progress more rapidly and the risk of serious events increases markedly. See /conditions/breathlessness for more.
Echocardiography (see /conditions/what-is-an-echocardiogram) is the primary tool. It measures the valve area, the pressure gradient across the valve, and the speed of blood flow through the narrowed opening — all of which grade severity as mild, moderate, or severe. Serial echocardiograms track progression over time.
Mild and moderate aortic stenosis without symptoms is managed with regular echocardiographic monitoring. There is no medication that reverses or slows the valve narrowing itself. Significant stenosis with symptoms requires valve replacement — either surgical aortic valve replacement (SAVR) or the less invasive transcatheter approach (TAVI), chosen based on age, surgical risk, and anatomy.
Severe symptomatic aortic stenosis carries a significant prognosis if untreated. Valve replacement, when indicated, dramatically improves both symptoms and long-term outlook.
Mild stenosis typically requires an echocardiogram every 3–5 years, moderate stenosis every 1–2 years, and severe stenosis at least annually or more frequently if symptoms develop.
Yes. TAVI (transcatheter aortic valve implantation) is a minimally invasive alternative increasingly used across age groups, particularly for patients at higher surgical risk.
A bicuspid aortic valve is a congenital abnormality affecting approximately 1–2% of the population. It predisposes to earlier aortic stenosis and aortic root dilation, both of which require lifelong echocardiographic surveillance.