Aortic Valve Stenosis

How aortic stenosis affects the heart

The aortic valve normally has three thin flaps (cusps) that open fully with each heartbeat. In aortic stenosis, the flaps thicken, stiffen and fuse, so the opening narrows from a normal area of about 3 to 4 cm² to less than 1 cm² in severe disease.

The left ventricle must generate higher pressure to push blood through. At first it adapts by thickening (hypertrophy). Over time:

• the thick muscle needs more oxygen than the coronary arteries can supply, causing chest pain
• the heart cannot increase output during exercise, causing breathlessness and dizziness
• the stiff, overworked ventricle eventually weakens, leading to heart failure

Stenosis usually worsens slowly over years, but once symptoms appear in severe stenosis, the outlook without treatment is poor.

Causes

Risk factors for calcific stenosis include age, high blood pressure, high LDL cholesterol, lipoprotein(a), smoking, diabetes and chronic kidney disease.

Symptoms

Many people have no symptoms for years. When symptoms develop, the three classic ones are:

• breathlessness, at first with exertion, later at rest or lying flat
• chest pain or tightness (angina) with exertion
• dizziness or fainting (syncope), often during or just after exertion

Other symptoms:

• tiredness and reduced ability to exercise, which older adults may put down to age
• palpitations, sometimes from atrial fibrillation
• ankle swelling as heart failure develops

Stages of aortic stenosis

Doctors grade severity mainly with echocardiogram measurements:

The ACC/AHA guideline also groups patients into stages A to D, from at-risk (A) through progressive (B), severe without symptoms (C) and severe with symptoms (D).

Diagnosis

• Heart murmur: a harsh, crescendo-decrescendo murmur heard best on the upper right side of the breastbone, often spreading to the neck.
• Echocardiogram: the main test. It shows the valve anatomy, measures blood speed and valve area, and assesses heart muscle function.
• ECG: may show thickening of the heart muscle or rhythm problems.
• Exercise testing: carefully supervised, in people who say they have no symptoms, to uncover hidden symptoms.
• CT scan: calcium scoring of the valve when echo results are unclear, and to plan TAVR.
• Cardiac catheterization: to check the coronary arteries before valve replacement.
• Blood tests: BNP, a marker of heart strain.

Treatment

Monitoring

There is no medicine that stops the valve from narrowing. People with mild or moderate stenosis have echocardiograms at regular intervals (roughly every 3 to 5 years for mild, 1 to 2 years for moderate, 6 to 12 months for severe). Control of blood pressure and cholesterol is important for overall heart health. Report any new symptom promptly.

When valve replacement is recommended

• severe aortic stenosis with symptoms
• severe stenosis with a weakening left ventricle (ejection fraction below 50%), even without symptoms
• severe stenosis when another heart operation is planned
• selected people with very severe or rapidly progressing stenosis without symptoms

TAVR vs surgical valve replacement

The choice is made by a heart team of cardiologists and surgeons, based on age, health, anatomy and preference. Mechanical valves last longest but require lifelong blood thinners (warfarin). Tissue valves avoid long-term warfarin but may wear out after 10 to 20 years.

Balloon valvuloplasty stretches the valve temporarily and is used mainly as a bridge to replacement or in children.

Complications

• heart failure
• sudden cardiac death, mostly in people with symptoms
• atrial fibrillation and other arrhythmias
• endocarditis, infection of the valve
• bleeding from the gut (Heyde syndrome), linked to a blood clotting protein being damaged by the narrowed valve

Outlook

People with mild or moderate stenosis without symptoms have an outlook close to normal but need monitoring. Once severe stenosis causes symptoms, about half of untreated people die within around 2 years. Valve replacement relieves symptoms and restores life expectancy close to that of people of the same age.

Frequently asked questions

What are the symptoms of aortic valve stenosis?

The main symptoms are breathlessness during activity, chest pain or tightness, dizziness or fainting during exertion, and tiredness. Many people have no symptoms for years. Once symptoms appear in severe stenosis, valve replacement is usually needed.

How fast does aortic stenosis progress?

It usually progresses slowly. On average, the valve area shrinks by about 0.1 cm² a year and the pressure gradient rises by a few mmHg a year, but the rate varies widely. Regular echocardiograms track progression.

What is the life expectancy with severe aortic stenosis?

Without valve replacement, about half of people with severe, symptomatic aortic stenosis die within about 2 years. After successful replacement, life expectancy is close to that of others of the same age.

Is TAVR better than open-heart surgery?

For many people over 65 to 80, TAVR is as effective as surgery with faster recovery. Surgery may be better for younger people, bicuspid valves unsuitable for TAVR, or when other heart surgery is needed. A heart team helps choose.

Can aortic stenosis be treated with medicine?

No medicine can reverse or slow the narrowing of the valve. Medicines can treat blood pressure, heart failure symptoms or atrial fibrillation, but valve replacement is the only treatment for severe aortic stenosis.