---
title: Aortic stenosis
description: What aortic stenosis is, why it develops, how it is detected and which treatment approaches clinical guidelines describe.
type: disease
preset: aortic-stenosis
aliases:
  - AS
  - aortic valve stenosis
sources:
  - tier: guideline
    org: esc
    title: 2025 ESC/EACTS Guidelines for the management of valvular heart disease
    year: 2025
    doi: 10.1093/eurheartj/ehaf194
    url: https://doi.org/10.1093/eurheartj/ehaf194
  - tier: guideline
    org: aha-acc
    title: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease
    year: 2020
    doi: 10.1161/CIR.0000000000000923
    url: https://doi.org/10.1161/CIR.0000000000000923
  - tier: guideline
    org: minzdrav-rf
    title: Аортальный стеноз
    year: 2025
    url: https://cr.minzdrav.gov.ru/view-cr/37_2
  - tier: guideline
    org: nice
    title: 'Heart valve disease presenting in adults: investigation and management (NG208)'
    year: 2021
    url: https://www.nice.org.uk/guidance/ng208
  - tier: reference
    org: msd-manuals
    title: Aortic Stenosis
    year: 2025
    url: https://www.msdmanuals.com/professional/cardiovascular-disorders/valvular-disorders/aortic-stenosis
  - tier: reference
    org: msd-manuals
    title: Cardiac Auscultation
    year: 2025
    url: https://www.msdmanuals.com/professional/cardiovascular-disorders/approach-to-the-cardiac-patient/cardiac-auscultation
sources_checked: 2026-10-11
review: null
---

Aortic stenosis is a narrowing of the aortic opening where blood leaves the <Structure id="left-ventricle">left ventricle</Structure>; the narrowing gets in the way of normal blood flow into the <Structure id="aorta">aorta</Structure>.<Cite n={3} /> For a long time it causes no symptoms and is often found by chance.<Cite n={3} />

<Diagram name="aortic-stenosis">
  <p slot="normal">
    Normally blood leaves the left ventricle and flows into the aorta through the valve; a normal
    valve has three leaflets.<Cite n={3} />
  </p>
  <p slot="disease">
    In aortic stenosis the aortic opening is narrowed, in adults most often by calcium building up
    on the valve leaflets, and this gets in the way of normal blood flow into the
    aorta.<Cite n={3} /> Blood speeds up through the valve: in severe stenosis the peak velocity is
    4 m/s or more.<Cite n={2} />
  </p>
  <p slot="treated">
    After the procedure the narrowed valve has been replaced with a prosthesis: it is put in during
    open-heart surgery or through a blood vessel using a catheter (TAVI).<Cite n={[2, 3, 4]} /> A
    team of doctors decides on the method together with the patient.<Cite n={[1, 2, 3, 4]} /> After
    the replacement the person stays under a cardiologist's follow-up with echocardiography: a
    prosthesis can wear out over time or leak around its edge.<Cite n={[3, 4]} />
  </p>
</Diagram>

## Why it happens

<Patient>

In adults the most common cause is calcium building up on the <Structure id="aortic-valve">valve</Structure> leaflets. This happens both in a normal valve with three leaflets and in a valve with two leaflets that a person is born with.<Cite n={3} /> In young people stenosis is more often due to a valve defect present from birth.<Cite n={3} /> Stenosis after rheumatic fever is now much less common.<Cite n={3} /> Aortic stenosis becomes more common with age.<Cite n={3} />

The narrowing usually worsens gradually, and over time most people develop symptoms.<Cite n={2} />

</Patient>

<Student>

The most common cause in adults is calcification of the leaflets of a normal tricuspid or a congenital bicuspid valve; calcific aortic stenosis is regarded as an active disease process with inflammation and calcification.<Cite n={3} /> Rheumatic stenosis results from commissural fusion, is now much less common and is usually accompanied by mitral valve disease.<Cite n={3} /> Prevalence rises with age: 0.2% under 65 years, 1.3% at 65–74 years and 2.8% over 75 years.<Cite n={3} />

The ACC/AHA guideline defines stages: A, at risk of AS (for example, a bicuspid valve or aortic valve sclerosis); B, progressive AS; C, asymptomatic severe AS; D, symptomatic severe AS.<Cite n={2} /> Haemodynamic progression eventually leading to symptom onset occurs in nearly all asymptomatic patients once the aortic velocity reaches 2 m/s or more.<Cite n={2} />

</Student>

## Symptoms

<Patient>

The most common first sign is breathlessness on exertion, or finding that exercise has become harder to manage.<Cite n={2} /> As the stenosis progresses, chest pain (angina) and fainting are typical.<Cite n={3} /> Breathlessness at rest and an irregular or skipping heartbeat are also common.<Cite n={3} />

Because the disease develops slowly, a person may cut back on activity over years without realising it and not notice symptoms.<Cite n={1} /> This matters: once symptoms appear, the risk of sudden death rises sharply unless the valve is treated.<Cite n={[1, 3]} />

</Patient>

<Student>

The most common initial symptom is exertional dyspnoea or decreased exercise tolerance; more severe "classical" symptoms include heart failure, syncope and angina.<Cite n={2} /> For stage D1 the listed symptoms are exertional dyspnoea, decreased exercise tolerance or heart failure, exertional angina, and exertional syncope or presyncope.<Cite n={2} /> Arrhythmias are common: ventricular premature beats and atrial fibrillation.<Cite n={3} />

According to the Russian Ministry of Health guideline, once symptoms appear the risk of sudden death increases and life expectancy is two to three years; the European guideline stresses that the risk rises sharply unless a valve intervention is performed.<Cite n={[1, 3]} />

</Student>

## How it is diagnosed

<Patient>

When listening to the heart, the doctor may hear a harsh murmur.<Cite n={3} /> The key test is an ultrasound scan of the heart (echocardiogram). It is done for everyone suspected of having aortic stenosis: it shows how the valve is built and how narrow it is.<Cite n={[2, 3]} />

If a doctor suspects valve disease because of a heart murmur and there is breathlessness or chest pain, guidelines advise an echocardiogram.<Cite n={4} /> If a murmur comes with fainting on exertion, guidelines advise seeing a specialist and having an echocardiogram within two weeks.<Cite n={4} />

</Patient>

<Student>

On auscultation there is a harsh systolic murmur over the aortic area and over the mitral valve.<Cite n={3} /> Comprehensive transthoracic echocardiography is the first-line examination: it confirms valve dysfunction and determines the aetiology, mechanism and severity of the lesion.<Cite n={1} /> The Russian Ministry of Health guideline recommends echocardiography for all patients with suspected or previously diagnosed aortic stenosis, for diagnosis and assessment of severity.<Cite n={3} />

Severe high-gradient AS according to ACC/AHA: aortic Vmax ≥4 m/s or mean gradient ≥40 mm Hg; aortic valve area is typically ≤1.0 cm² (or indexed ≤0.6 cm²/m²) but is not required to define severe AS.<Cite n={2} /> Very severe AS is an aortic Vmax ≥5 m/s or mean gradient ≥60 mm Hg.<Cite n={2} /> In asymptomatic severe AS, exercise testing helps confirm that there really are no symptoms.<Cite n={2} /> When noninvasive data are nondiagnostic, cardiac catheterisation can be helpful.<Cite n={2} />

</Student>

<HeartSounds sound="aortic-stenosis" />

## How it is treated

<Patient>

The main treatment for severe aortic stenosis is replacing the valve. This is done either by open-heart surgery or through a blood vessel using a catheter (transcatheter aortic valve implantation, TAVI).<Cite n={[2, 3, 4]} />

Whether a procedure is needed, and which one, is decided by a team of doctors (a cardiologist, a heart surgeon and imaging specialists) together with the patient and their family. The doctors explain the benefits and risks and take into account age, the risk of surgery and the person's own preferences.<Cite n={[1, 2, 4]} />

If severe stenosis is not yet causing symptoms and a procedure is not needed, the doctor sees the person regularly and arranges echocardiograms.<Cite n={4} />

</Patient>

<Student>

In symptomatic severe high-gradient AS (stage D1), aortic valve replacement improves survival, symptoms and left ventricular systolic function; symptoms provoked by exercise testing also count as a class 1 indication.<Cite n={2} /> NICE suggests considering referral for intervention in asymptomatic severe AS if any of the following is present: peak aortic jet velocity more than 5 m/s, aortic valve area less than 0.6 cm², left ventricular ejection fraction less than 55%, BNP or NT-proBNP more than twice the upper limit of normal, or symptoms unmasked on exercise testing.<Cite n={4} />

Guidelines from different countries frame the choice between surgical aortic valve replacement (SAVR) and TAVI differently. ACC/AHA recommend SAVR for patients under 65 years unless life expectancy is limited by comorbid conditions, and consider both approaches effective at 65–80 years; the choice is a shared decision that weighs lifetime risks and benefits.<Cite n={2} /> NICE offers surgery as first-line intervention for people at low or intermediate surgical risk, and TAVI for non-bicuspid severe aortic stenosis when surgical risk is high or surgery is unsuitable. NICE is currently updating these TAVI recommendations.<Cite n={4} /> The 2025 European guideline refines the Heart Team criteria for choosing between TAVI and SAVR: they combine age, procedural risk and anatomical suitability, and take into account estimated life expectancy and lifetime management.<Cite n={1} /> The decision is made by the Heart Team (the treating cardiologist, imaging specialists, cardiac surgeons and interventional cardiologists), and the final decision is shared with the informed patient.<Cite n={1} />

At the time the ACC/AHA guideline was published, there were no data to support statins for slowing the progression of aortic stenosis.<Cite n={2} /> In asymptomatic severe AS when intervention is not yet needed, NICE offers clinical review with an echocardiogram every 6–12 months; the frequency of review is based on echocardiography findings and shared decision-making with the patient.<Cite n={4} />

</Student>

## When to call an ambulance

If a person with aortic stenosis develops breathlessness on exertion, chest pain or feeling faint on exertion for the first time, they should see a cardiologist without delay: once symptoms appear, the risk rises sharply unless the valve is treated.<Cite n={[1, 2]} />

Aortic stenosis can suddenly decompensate, even to the point of cardiogenic shock.<Cite n={1} /> If a person with aortic stenosis faints, has severe chest pain or sudden severe breathlessness, call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK).<Cite n={[1, 2]} />

<Quiz />