Aortic valve stenosis

What aortic stenosis is

The aortic valve sits between the left ventricle and the aorta, the body’s largest artery. It normally has three thin leaflets that open wide with every beat and close tightly between beats so blood cannot flow backward. In aortic stenosis the leaflets thicken, stiffen and open only partly. The heart must push harder to eject the same amount of blood, so the wall of the left ventricle thickens (see left ventricular hypertrophy). At first this compensates, but with time the heart tires and heart failure may appear.

The disease progresses slowly and unevenly from person to person. Some have mild stenosis for ten years, others move faster toward the severe form. It is one of the most common valve diseases in older adults (see also valve diseases).

Causes

• Age-related degenerative calcification, the most common cause, especially after age 65–70. Calcium is deposited gradually in the leaflets in a process that resembles atherosclerosis; factors such as hypertension, high cholesterol and smoking may speed it up.
• Bicuspid valve: a valve with two leaflets instead of three, present from birth and often unknown until later. Stenosis appears earlier, often between ages 40 and 60.
• Rheumatic heart disease, a rarer cause today but still present in some older patients.

Symptoms

At first there are no complaints, even when the valve has narrowed considerably. As the disease advances, the following may appear, especially on exertion:

• shortness of breath and reduced ability to be active, often blamed on age;
• chest pain or tightness, resembling angina even when the coronary arteries are healthy;
• dizziness or fainting, especially during or after exertion.

The appearance of symptoms is a key moment: it usually means it is time for treatment, because from then on the course without intervention worsens quickly. It is therefore important not to “adapt” silently by doing less, and to tell your doctor about any change.

How it is diagnosed

The doctor often suspects the disease from a characteristic murmur heard with a stethoscope. Confirmation comes from echocardiography, the main test: it measures the speed of blood through the valve, the gradient (the pressure difference across the valve), the valve opening area and the function of the left ventricle (see echocardiography). Some cases call for further tests, such as a CT calcium score of the valve, which helps when ultrasound measurements do not agree, or CT/coronary angiography before an intervention to look at the coronary arteries.

The decision is not made from one number in a report but from how the measurements fit with symptoms, heart function and the patient’s overall condition. For this reason it is unwise to interpret an isolated ultrasound value yourself.

Follow-up and treatment

Mild or moderate stenosis: periodic follow-up with echocardiography (usually every 6 months to a year, according to severity and course, or sooner when the doctor considers it reasonable) and control of risk factors such as blood pressure. Medicines treat accompanying conditions, but they do not open the calcified valve; no drug makes stenosis go away.

Severe stenosis with symptoms (and some severe cases without symptoms, when there are risk markers or a fall in ventricular function) is treated with valve replacement, which noticeably changes the course:

• surgical replacement (SAVR): open-heart surgery, with a biological or mechanical valve. A mechanical valve needs lifelong anticoagulation; a biological valve lasts less long but usually needs only temporary medicines;
• transcatheter replacement (TAVI/TAVR): the new valve is delivered through an artery, usually in the groin, without opening the chest. Recovery is faster and it is increasingly used, especially in older patients or those at higher surgical risk.

The choice is made by the heart team (cardiologist, cardiac surgeon, imaging specialist, sometimes an anesthesiologist), considering age, the anatomy of the valve and aorta, surgical risk, accompanying diseases and the patient’s preferences. After replacement, regular follow-up with echocardiography is needed.

Physical activity and daily life

Activity is adjusted to the degree of stenosis. With mild stenosis most activities are allowed; with severe stenosis heavy exertion, such as lifting very heavy weights or intense sport, is avoided. An exercise test may be recommended by the cardiologist only in selected cases, when severe stenosis causes no symptoms; in patients with symptoms it is not done. Dental work and other procedures may require special precautions if you have a replaced valve; ask your cardiologist.

This information is educational and does not replace a medical visit.