Aortic Stenosis

Aortic stenosis is a heart condition where the aortic valve becomes narrowed and doesn’t open fully, making it harder for your heart to pump blood to the rest of your body. While many people live without symptoms for years, this condition can become serious if left untreated, potentially leading to heart failure or even death.

Table of contents

• What is aortic stenosis?
• Associated anatomy
• What causes aortic stenosis?
• How common is this condition?
• What are the symptoms?
• How does the condition progress?
• How is aortic stenosis diagnosed?
• Treatment options
• Living with aortic stenosis

What is aortic stenosis?

Aortic stenosis is a common type of heart valve disease that affects the aortic valve, which sits between the lower left chamber of your heart and the body’s main artery, called the aorta^[1]. The normal aortic valve has three leaflets (flaps) that open to let blood pass through and then seal shut to keep blood from flowing backward^[4].

In aortic stenosis, the valve becomes narrowed and doesn’t open fully. This reduces or blocks blood flow from your heart to the rest of your body^[1]. When this happens, your heart has to work much harder to pump blood through the narrowed opening. Over time, this extra work can damage your heart muscle and lead to serious health problems^[4].

The condition develops when the valve leaflets become thickened, stiff, or scarred. As the valve narrows, the left ventricle (the heart’s main pumping chamber) must squeeze harder to push blood through. To handle this extra work, the muscles in the ventricle walls become thicker^[6]. This thickening is the heart’s way of compensating, but eventually these changes become inadequate to maintain proper blood flow^[3].

• Aortic valve
• Aorta
• Left ventricle
• Heart

What causes aortic stenosis?

Aortic stenosis has several different causes, and the most common one depends on your age^[4].

Age-related wear and tear is the most common cause in people over 65. Over time, calcium can build up on the valve, making it stiff and limiting blood flow. This process is similar to what happens in atherosclerosis (hardening of the arteries), involving lipid accumulation, inflammation, and calcification^[12]. About 2 to 9% of people aged greater than 75 have severe aortic stenosis^[3].

Congenital abnormalities present at birth are the most common cause in people younger than 70 in developed countries. Some people are born with a bicuspid aortic valve, which means their valve has only two leaflets instead of the normal three^[3]. This abnormal structure makes the valve more likely to become damaged over time.

Rheumatic fever, which can develop after untreated strep throat or scarlet fever, is the most common cause in developing countries^[3]. When rheumatic fever damages heart valves, the leaflets’ edges fuse together, leaving only a small central opening^[3]. It may take years or decades before valve damage from rheumatic fever becomes apparent^[4]. This condition is rare in the United States today^[6].

Other less common causes include kidney failure, certain inherited conditions like familial hypercholesterolemia, autoimmune diseases such as lupus and rheumatoid arthritis, radiation treatment for cancer, and various metabolic diseases^[3][4].

Risk factors that increase your chances of developing aortic stenosis include being male, being older, having high blood pressure, high cholesterol, smoking, chronic kidney disease, and a history of rheumatic heart disease^[4][8].

How common is this condition?

Aortic stenosis is particularly common in older adults. The condition affects about 3% of people over 65 years of age^[12]. As people age, the prevalence increases significantly—about 2 to 9% of people older than 75 have severe aortic stenosis^[3].

Aortic stenosis is common in people over 65, but many don’t know they have it until it causes symptoms or shows up on a screening test^[4]. Up to 50% of individuals with mild or moderate aortic stenosis may not experience noticeable symptoms until the disease progresses^[21].

The condition occurs more often in men than in women^[6]. In rare instances, children can have a congenital condition that causes aortic valve stenosis^[4].

What are the symptoms?

One of the challenging aspects of aortic stenosis is that it often develops slowly without causing symptoms for many years. Symptoms typically develop gradually after a long asymptomatic period of about 10 to 20 years^[3]. Most people with aortic stenosis do not develop symptoms until the disease is advanced^[6].

During this symptom-free period, the condition may be discovered when a doctor hears a heart murmur (an abnormal sound) through a stethoscope during a routine physical exam^[5][6].

When symptoms do appear, they often occur with physical activity or exercise and may include^[4][8]:

• Fatigue that disrupts your normal activities and makes you feel easily tired
• Shortness of breath, especially during exercise or exertion
• Chest pain or discomfort (also called angina), which can feel like squeezing, pressure, or tightness and may extend to your neck, jaw, arm, or abdomen
• Dizziness, lightheadedness, or fainting spells, particularly during activity
• Heart palpitations (being unpleasantly aware of your own heartbeat)
• Swelling in your feet, ankles, or lower legs

In infants and children with aortic stenosis, symptoms can include becoming easily tired with exertion, failure to gain weight, poor feeding, and in severe cases, serious breathing problems that develop within days or weeks of birth^[6].

It’s important to report any of these symptoms to your doctor right away, as they could indicate that your condition is worsening^[15].

How does the condition progress?

Aortic stenosis has a prolonged period without symptoms, during which the condition gradually worsens. The valve opening slowly becomes narrower over time as calcium builds up or the leaflets become stiffer^[12].

During the symptom-free period, your heart adapts to the increasing workload. The left ventricle develops thicker walls (a process called hypertrophy) to help maintain adequate blood pressure throughout your body^[12]. Your heart’s upper chamber (the left atrium) also works harder to fill the ventricle with blood^[12].

While survival during the asymptomatic phase is comparable to that of people without the condition, the situation changes dramatically once symptoms appear. Without treatment, mortality is more than 90% within a few years after the onset of symptoms^[3]. Survival decreases rapidly after symptoms develop^[12].

The speed of progression varies from person to person. For some people, aortic valve stenosis can happen slowly and take several years. For others, it can happen much faster^[4]. If you wait too long for treatment, you may develop heart damage that cannot be repaired or reversed. In cases of severe aortic stenosis, there’s also a risk of dying suddenly^[4].

As the condition worsens and compensatory mechanisms become inadequate, blood may back up into the lungs, and severe aortic stenosis can limit the amount of blood reaching the brain and rest of the body^[6]. This can lead to symptoms of heart failure, chest pain (angina), or fainting (syncope)^[3].

How is aortic stenosis diagnosed?

Doctors often first suspect aortic stenosis when they hear an abnormal heart sound called a murmur through a stethoscope during a physical exam^[5][6]. They may also be able to feel a vibration or movement when placing a hand over your heart^[6].

To confirm the diagnosis and determine how severe the condition is, your doctor will use several tests^[9]:

Echocardiography (ultrasound of the heart) is the main test for diagnosing and monitoring aortic stenosis. This test uses sound waves to create pictures of your beating heart^[9]. It shows how blood flows through the heart and valves, can tell how severe the stenosis is, and can reveal if your heart muscle is weakened^[9]. A standard echocardiogram is performed from outside your body by moving an ultrasound device over your chest. Sometimes a more detailed test called a transesophageal echocardiogram is needed, where the ultrasound device is inserted down your throat to get closer images of your heart^[9].

An electrocardiogram (ECG or EKG) records the electrical activity of your heart. This quick test uses sticky patches with sensors placed on your chest and sometimes legs. It can show signal patterns related to heart disease or swelling of the heart’s chambers^[9].

A chest X-ray shows the condition of your heart and lungs. It can reveal if your heart is bigger than usual, which can occur in aortic valve stenosis, and can also show if there are signs of fluid buildup in the lungs^[9].

An exercise stress test may be performed if you have aortic stenosis but don’t have symptoms. If the stress test shows a problem or if you have symptoms, doctors may do cardiac catheterization to find out if you also have coronary artery disease. This is important because if you need surgery for aortic stenosis, doctors can fix both problems at the same time^[5].

Based on the severity of your condition, your doctor will recommend regular monitoring with these tests. For people without symptoms, echocardiography is typically recommended every six to 12 months for severe aortic stenosis, every one to two years for moderate disease, and every three to five years for mild disease^[6][12].

Treatment options

Treatment for aortic stenosis depends on how severe your condition is, whether you have symptoms, and your overall health^[6].

Monitoring without immediate treatment

If you’re an adult with aortic stenosis but don’t have symptoms, regular checkups and monitoring may be all that’s needed^[6][12]. Watchful waiting is recommended for most patients without symptoms^[12]. During this time, you should:

• See your doctor regularly
• Avoid overly stressful exercise
• Have echocardiography occasionally, as your doctor recommends^[5]

Your doctor may prescribe medications to help control symptoms or manage other heart conditions, but medications cannot slow the progression of aortic stenosis itself^[18]. Medicines may be used to treat symptoms of heart failure or abnormal heart rhythms, and can include diuretics (water pills), nitrates, and beta-blockers^[6].

Valve replacement

Aortic valve replacement is the only treatment that improves survival in patients with symptomatic severe aortic stenosis^[12]. If you have symptoms or if your left ventricle begins to fail, you will eventually need your valve replaced^[7]. Without a replacement valve, severe aortic stenosis can lead to heart failure and death^[7].

There are two main approaches for valve replacement:

Surgical Aortic Valve Replacement (SAVR) is traditional open-heart surgery where surgeons repair or replace the faulty valve. This is the standard of care for patients at low to moderate surgical risk^[13]. During surgery, the damaged valve is removed and replaced with either a mechanical valve (made of metal and carbon) or a bioprosthetic valve (made from human or animal tissue, such as from a pig or cow heart)^[5].

If you receive a mechanical valve, you’ll need to take blood-thinning medicine for the rest of your life, but the valve may last several decades. If you get a bioprosthetic valve, you’ll only need blood-thinning medicine for a few months, but the valve typically lasts only 10 to 12 years^[5]. Currently, TAVR valves typically last between 8-10 years, while surgical valves can last up to 15-20 years^[7].

Transcatheter Aortic Valve Replacement (TAVR) is a newer, less invasive procedure performed through a small tube (catheter) inserted in a blood vessel, usually in the leg^[7]. The replacement valve and instruments are guided through the blood vessel using advanced imaging. Once in place, the new valve is implanted into the diseased valve and takes over its function^[7].

TAVR was initially developed for patients who were too sick or frail for open-heart surgery. However, after studies proved it was safe and effective, heart specialists now recommend it as the first option for many people who need an aortic valve replacement, particularly elderly patients^[13][18]. TAVR is recommended for patients at prohibitive surgical risk and is a reasonable alternative for high-risk patients^[13].

Unlike open-heart surgery, TAVR is usually performed with local anesthesia and sedation, which means fewer complications, no chest scarring, and a faster recovery. Hospital stays are much shorter—patients typically go home the next day^[7][18].

For children and young adults born with valve problems, doctors may perform a procedure called balloon valvotomy. The doctor inserts a thin catheter into the heart and inflates a balloon on its tip to push the valve open. However, this procedure doesn’t work very well for older adults^[5].

Living with aortic stenosis

Patients with aortic stenosis can live full and rewarding lives^[15]. More than 60% of patients report favorable outcomes one year after valve replacement procedures, with substantial increases in health status scores^[21]. However, they need to be monitored by a heart specialist with office visits and periodic testing^[15].

Monitoring your condition

If you’ve been diagnosed with aortic stenosis but don’t yet have symptoms, it’s crucial to watch for warning signs. Any of these symptoms should be reported at once to your family doctor or heart specialist: chest pain or discomfort, difficulty breathing, or lightheadedness or fainting spells. These symptoms could indicate a worsening of your condition^[15].

Based on the severity of your condition, your doctor may limit your activity, but many patients can exercise and do most activities without restriction^[15]. However, people with severe aortic stenosis may be told not to play competitive sports, even if they have no symptoms^[6]. You should only increase activity or start an exercise program under the guidance of your doctor^[15].

Because aortic stenosis tends to progress over time, even patients without symptoms require routine testing to monitor their condition. This typically includes echocardiograms and other tests such as exercise stress tests. Occasionally, more invasive testing such as heart catheterization may be needed^[15].

After valve replacement

If you’ve undergone valve replacement treatment, continuous monitoring of heart health is vital for ensuring your recovery remains on track and preventing any future complications^[21]. Your doctor will schedule regular follow-ups to check the function of your new valve and monitor for any complications. Staying active within the limits advised by your doctor and maintaining a heart-healthy lifestyle can further support long-term recovery^[21].

Preventing complications

While there are no proven ways to prevent aortic stenosis from developing, managing risk factors like high blood pressure, high cholesterol, and smoking may help^[8]. If you have a damaged or replaced valve, you may sometimes need antibiotics to prevent heart valve infection when undergoing certain medical or dental procedures^[5], though current guidelines have become more selective about when this is necessary^[6].