Aortic Stenosis

How aortic stenosis affects the heart

The aortic valve normally has three thin leaflets that open fully with each heartbeat. In aortic stenosis, the leaflets thicken, stiffen and fuse, so the opening narrows. A normal valve area is about 3 to 4 cm². Severe stenosis is usually below 1 cm².

To push blood through the narrow valve, the left ventricle generates higher pressure and its wall thickens (hypertrophy). This compensates for years, often without symptoms. Eventually:

• the thick muscle needs more oxygen than the coronary arteries can supply, causing angina
• the stiff ventricle fills poorly, raising pressure in the lungs and causing breathlessness
• the heart cannot increase output during exercise, so blood pressure can drop, causing dizziness or fainting
• the ventricle finally weakens, leading to heart failure

Symptoms

Symptoms usually appear only when stenosis is severe. Many people reduce their activity without realizing, so doctors ask carefully about exercise tolerance.

• Breathlessness on exertion, the most common first symptom
• Fatigue and reduced exercise capacity
• Chest pain or tightness (angina) with exertion
• Dizziness, light-headedness or fainting (syncope) during or just after exertion
• Palpitations
• Symptoms of heart failure: breathlessness lying flat, waking breathless, swollen ankles

Some people also develop bleeding from the gut because the narrowed valve breaks down a clotting protein, a combination called Heyde syndrome, linked with angiodysplasia.

Causes and risk factors

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

Diagnosis

Examination

A doctor hears a characteristic harsh systolic murmur best at the upper right of the breastbone, often spreading to the neck. In severe stenosis the pulse may rise slowly and feel weak.

Echocardiogram

An ultrasound of the heart is the key test. It measures:

• Peak velocity of blood through the valve
• Mean pressure gradient across the valve
• Valve area
• Left ventricular function (ejection fraction) and wall thickness

Other tests

• ECG: may show ventricular thickening or rhythm problems
• Exercise testing: in people who report no symptoms, to reveal hidden symptoms or abnormal blood pressure response
• CT scan: calcium scoring when severity is unclear, and planning for TAVR
• Coronary angiography: to check for coronary artery disease before valve replacement
• BNP blood test: helps assess heart strain

Treatment

Monitoring

There is no medicine that slows or reverses aortic stenosis. People with mild or moderate stenosis are monitored with echocardiograms, typically every 3 to 5 years for mild, 1 to 2 years for moderate, and every 6 to 12 months for severe stenosis without symptoms. Report any new symptoms promptly rather than waiting for the next scan.

Managing related conditions

Blood pressure, cholesterol, diabetes and dental health are managed as usual. Good dental hygiene lowers the risk of valve infection (endocarditis). Medicines for heart failure symptoms and atrial fibrillation are used carefully.

Valve replacement

Valve replacement is recommended for severe aortic stenosis with symptoms, and for some people without symptoms who have a weakening heart, very severe stenosis, or an abnormal exercise test.

• Transcatheter aortic valve replacement (TAVR or TAVI): a new valve is threaded on a catheter, usually from the groin artery, and expanded inside the old valve. No open-heart surgery is needed, and most people go home within 1 to 2 days. It is now widely used, especially in people over 65 to 75.
• Surgical aortic valve replacement (SAVR): open-heart surgery to replace the valve with a mechanical or tissue valve. Often preferred in younger people, those with bicuspid valves unsuitable for TAVR, or those needing other heart surgery. Mechanical valves last longer but need lifelong warfarin.
• Balloon valvuloplasty: temporarily widens the valve, used in children or as a bridge in very ill adults.

The choice is made by a heart team based on age, life expectancy, valve anatomy, other illnesses and personal preference.

Living with aortic stenosis

• People with mild or moderate stenosis can usually exercise normally. With severe stenosis, avoid heavy lifting and competitive or very strenuous exercise until you have been assessed.
• Stay well hydrated, and be careful with medicines that lower blood pressure suddenly.
• Tell your dentist and other doctors about your valve condition.
• Women with significant stenosis should get specialist advice before pregnancy.

Outlook

People can live without symptoms for many years with mild or moderate stenosis, but the narrowing usually worsens over time. Once severe stenosis causes symptoms, the outlook without valve replacement is poor, with many people dying within 2 to 3 years. After successful TAVR or surgery, symptoms usually improve dramatically and survival approaches that of people of the same age without valve disease.

Frequently asked questions

What are the first symptoms of aortic stenosis?

The earliest symptoms are usually breathlessness or tiredness during exercise and a gradual drop in how much you can do. Chest tightness, dizziness or fainting with exertion are warning signs of severe stenosis and need prompt assessment.

What causes aortic stenosis?

In older adults the most common cause is calcium buildup on the valve with age. In younger adults it is usually a bicuspid valve, which has two leaflets instead of three from birth. Rheumatic fever is a common cause worldwide.

What is the treatment for severe aortic stenosis?

Severe aortic stenosis with symptoms is treated by replacing the valve, either with TAVR, through a catheter, or with open-heart surgery. No medicine can open a narrowed valve, but medicines may ease symptoms while waiting for replacement.

What is the life expectancy with aortic stenosis?

With mild or moderate stenosis and no symptoms, life expectancy is often near normal with monitoring. Untreated severe stenosis with symptoms has a poor outlook, often 2 to 3 years. After valve replacement, life expectancy is close to that of the general population.

Can you exercise with aortic stenosis?

With mild to moderate stenosis, most moderate exercise is safe. With severe stenosis, strenuous exercise and heavy lifting should be avoided until a cardiologist has assessed you, because exertion can trigger fainting or chest pain.