Aortic Valve Stenosis: An Overview

Aortic Valve Stenosis Explained

Aortic valve stenosis, commonly referred to as aortic stenosis, occurs when the aortic valve in the heart becomes narrowed or obstructed. This condition disrupts the normal flow of blood from the heart, potentially leading to severe heart damage, health complications, and even death. The restricted blood flow limits oxygen supply to the body, which can manifest as chest pain, shortness of breath, and fainting.

Who is at Risk?

Aortic stenosis primarily affects older adults, particularly those over the age of 65. It can also develop in middle-aged individuals due to various diseases. In rare cases, children may be born with an aortic valve defect leading to stenosis.

Prevalence of the Condition

Approximately 2% of individuals over 65 in the U.S. experience some degree of aortic stenosis. Many remain unaware of the condition until it is identified through symptoms or diagnostic tests.

Causes and Symptoms

The aortic valve is crucial for blood flow, operating as the final valve that blood passes through before circulating into the body. It typically comprises three flaps (leaflets) that open and close to regulate blood flow. Aortic stenosis can arise from insufficiency (inadequate blood flow through the valve) or regurgitation (inability of the valve to close properly).

The three main causes of aortic stenosis in adults
Wear and tear due to age: Over time, calcium can build up on the valve — similar to what cholesterol does to blood vessels with atherosclerosis — limiting blood flow. Lifestyle habits are also affected if and when stenosis occurs. This type of stenosis happens most commonly after age 65.
Damage from infections: When bacteria from untreated infections reach your bloodstream, they can accumulate on your heart valves. This causes your immune system to damage the valve itself. This is most likely to happen with strep throat or scarlet fever, which, when untreated, can cause rheumatic fever. This disease, which can damage your heart valves, is most often seen in those over 50. It may take years or decades before the damage to your heart valves becomes apparent.
Caused by other inherited or chronic conditions: Other rare conditions that can cause aortic valve stenosis are Paget’s disease of the bone, kidney failure and familial hypercholesterolemia. Aortic stenosis is also linked to autoimmune or inflammatory diseases like lupus and rheumatoid arthritis.

Symptoms Range From:

Symptoms of aortic stenosis (progressing from less severe to more severe) include:

● Fatigue, especially when it disrupts your normal activities or happens during activities that didn’t tire you out before.
● Heart palpitations, where you become unpleasantly aware of your own heartbeat.
● Swelling in your feet, ankles or lower legs.
● Chest pain (angina). This can also feel like squeezing, pressure or discomfort and it can extend from your chest to your neck, jaw, arm or abdomen.
● Shortness of breath.
● Dizziness, lightheadedness or fainting.

How fast does the condition progress?

For some people, aortic stenosis can happen slowly and take several years. For others, it can happen much faster. Waiting too long can result in heart damage that can’t be repaired or reversed. In cases of severe aortic stenosis, there’s also a risk of dying suddenly. Because of this, your healthcare provider may advise you not to delay treatment.

Diagnosing Aortic Stenosis

When aortic stenosis is suspected, your primary care provider may refer you to a cardiologist for further evaluation. Diagnosis of this condition is usually based on reported symptoms and a series of diagnostic tests:

1. Physical Examination: During a physical exam, the doctor will check for signs like swelling in the lower legs and ankles. Using a stethoscope, the doctor will listen to your heart for any irregular sounds, such as a heart murmur, which is often indicative of aortic stenosis.
2. Electrocardiogram (ECG or EKG): This test records the electrical activity of the heart and is performed using sensors attached to the chest. An ECG can help detect abnormalities in heart rhythm and structure.
3. Imaging Tests:
Chest X-ray: A simple and quick way to view the heart, lungs, and chest structure.
Angiography or Cardiac CT Scan: These imaging tests use X-rays and a special dye (contrast) to provide a detailed view of the heart’s structure and the surrounding blood vessels. The contrast enhances visibility on the scans, aiding in detailed assessment.
Echocardiogram: This ultrasound test provides live images of the heart in motion, allowing doctors to see the heart’s structure and function in real-time. A specialized version, the transesophageal echocardiogram, involves inserting a probe down the esophagus to get a closer and more detailed view of the heart.
4. Exercise Stress Testing: This test assesses how well your heart functions during physical activity. It is useful for determining the severity of aortic stenosis and understanding its impact on your everyday activities.
5. Cardiac Catheterization: In this procedure, a catheter is inserted into a blood vessel, typically in the groin, and guided to the heart. This allows the specialist to examine the heart from the inside, assess the severity of blockage, and measure the heart’s performance.
6. Heart MRI: This test uses a strong magnetic field to create detailed images of the heart and surrounding tissues, providing comprehensive information about heart structure and function without the use of radiation.
These diagnostic tools collectively help healthcare providers accurately diagnose aortic stenosis and tailor an appropriate treatment plan.

Management and Treatment

Can aortic stenosis be cured?
It’s possible to treat or even repair aortic stenosis, depending on when it’s found and the method used. If you have stenosis but no symptoms, your healthcare provider may advise you to simply monitor the issue with follow-up visits and tests. If you develop symptoms, your provider can offer you treatment options, including the following:

● Medication: Several different medications, including blood thinners and medications to treat heart rhythm disorders, are often used to treat milder cases of aortic valve stenosis.
● Valve repair: This involves a surgical procedure, using either aortic valve surgery or balloon valvuloplasty. During aortic valve surgery — using either a traditional or a minimally invasive approach — a surgeon makes an incision in your chest to directly reach and repair the valve. Balloon valvuloplasty is used in cases with limited damage with limited regurgitation. During this procedure, your surgeon inserts a catheter with a balloon attached to one of your arteries and then threads it up to your heart. Once there, they inflate the balloon to widen the narrowed aortic valve. Surgeons don’t use this option as much in people who are older, but it may help improve symptoms for people with critical stenosis until they can have their valve replaced.
● Valve replacement: In cases where valve repair isn’t indicated, valve replacement is an option. There is a variety of surgical and nonsurgical methods available. Aortic valve surgery replaces the valve rather than repairing it. The valve can be replaced with a donor valve (usually from an animal such as a cow or pig), a mechanical valve or a bioprosthetic valve. Another option is a Ross procedure, which uses your own pulmonary valve to replace your damaged aortic valve. A donor valve is then used to replace your pulmonary valve. Finally, a transcatheter aortic valve replacement (TAVR) allows the replacement of an aortic valve without surgery. This procedure involves inserting a catheter-based device into an artery and then threaded to your heart. In some cases, a “valve-in-valve” approach can place the new valve directly over top of the old one.

What types of replacement valves are there, and why choose one over another?

1. Human donor valve: These valves come from organ and tissue donors and remain frozen until needed. Donor valves are a good option if you can’t or don’t want to take blood-thinning medications for a long time. However, the donor valve will ultimately wear out and need replacement after about 15 to 20 years.
2. Animal valve: Made from animal tissue (usually pigs or cows), these are also a good option when you want to avoid taking blood-thinning medications. Animal valves last about 15 to 20 years.
3. Mechanical valve: These valves are often composed of pyrolytic carbon (which is similar to diamonds but with a different structure). These valves are extremely durable and easily accepted by your body. Some of them also have polyester knit fabric around their edges. If you have one of these valves placed, you’ll need to take blood thinners for the rest of your life to prevent problems like stroke. These valves are made to last for the rest of your lifetime.
4. Bioprosthetic valve: These valves often combine animal tissue and artificial parts. The animal tissue is usually attached to a metal frame, which keeps the valve in place. These valves typically last about 15 to 20 years.

Medication and Treatment Adherence

The type of treatment you undergo will determine whether you need to take medications temporarily or on a long-term basis. Your healthcare provider will provide specific instructions on which medications are necessary, how to take them, and the duration of treatment.

Recovery from Treatment

The recovery period after aortic valve stenosis treatment varies depending on the procedure performed. Surgical approaches generally require a longer hospital stay, often several days, with a full recovery extending over several weeks.

Minimally Invasive Procedures

Less invasive procedures, such as balloon valvuloplasty and transcatheter aortic valve replacement (TAVR), typically feature shorter recovery times. Often, patients may be able to go home the same day or the day after the procedure and can quickly return to their daily activities.

Conclusion

Aortic valve stenosis is a serious cardiovascular condition that can lead to significant health complications if left untreated. Understanding the nature of the disease, recognizing the symptoms early, and undergoing timely diagnosis are crucial steps toward effective management. Whether through lifestyle adjustments, medication, or surgical interventions, each treatment strategy is tailored to the individual's condition severity. Advances in medical procedures, especially less invasive techniques, offer hope and improved outcomes, making recovery quicker and less burdensome. It's essential for patients to work closely with their healthcare providers to navigate the options available for managing this condition effectively. By adhering to prescribed treatments and attending regular follow-up appointments, individuals with aortic stenosis can lead healthier and more active lives.