What is Aortic Valve Disease?
Aortic valve disease is a structural or functional deterioration that occurs in the aortic valve, which is located between the main blood vessel leaving the heart (aorta) and the left ventricle. A normal aortic valve consists of three leaflets and opens when the heart contracts (systole), allowing blood to pass from the left ventricle to the aorta. When the heart relaxes (diastole), it closes, preventing blood from flowing back from the aorta to the left ventricle. Aortic valve disease can manifest as the valve not opening completely (aortic stenosis), not closing completely (aortic regurgitation or insufficiency), or a combination of both conditions.
Aortic valve diseases are among the common heart valve problems in the population and become more prevalent with advancing age. Aortic stenosis caused by calcification of the aortic valve is particularly common in the elderly. On the other hand, aortic regurgitation can occur at any age and may stem from various causes. Early diagnosis and proper treatment can slow the progression of the disease, reduce symptoms, and improve quality of life.
Aortic valve diseases can range from mild conditions to serious problems that can put life at risk. While some individuals may not show any symptoms for many years, in others, the disease can progress rapidly and lead to significant complications.
What is Aortic Stenosis?
Aortic stenosis is a condition where the aortic valve does not open completely due to thickening, stiffening, or adhesion of the aortic valve leaflets. This creates an obstacle to the passage of blood from the left ventricle to the aorta and causes the heart to exert more effort to maintain normal blood flow. Over time, pressure in the left ventricle increases and its walls thicken (hypertrophy), leading to the heart muscle requiring more oxygen and becoming stiffer.
Aortic valve stenosis is the most common heart valve disease, especially in the elderly. In developed countries, the most common cause of aortic stenosis is age-related calcification (degenerative aortic stenosis). In this condition, calcium accumulates in the aortic valve leaflets as age advances, causing the valve to stiffen and thicken. Other causes include congenital problems (especially bicuspid aortic valve), history of rheumatic fever, and radiation therapy.
The severity of aortic valve stenosis is determined by the size of the valve opening and the pressure difference across the valve. In mild stenosis (valve area 1.5-2.0 cm²), symptoms are generally minimal or nonexistent. In moderate stenosis (valve area 1.0-1.5 cm²), symptoms may emerge during exercise. In severe stenosis (valve area < 1.0 cm²), symptoms are felt even at rest and treatment is necessary. Untreated aortic stenosis can lead to serious problems such as heart failure, chest pain (angina), fainting (syncope), and even sudden death.
What is Aortic Regurgitation?
Aortic regurgitation is a condition where the aortic valve, located between the main artery leaving the heart (aorta) and the left ventricle, cannot close completely. This problem leads to blood flowing back from the aorta to the left ventricle during the heart’s relaxation phase (diastole). In aortic regurgitation, the heart has to pump both this extra returning blood and the normal blood coming from the lungs. Over time, the left ventricle enlarges and its walls thicken (eccentric hypertrophy) to cope with this increased load. If left untreated, this condition can progress to heart failure.
Aortic valve regurgitation can occur acutely (suddenly) or chronically (developing slowly). Acute aortic regurgitation is usually seen in conditions such as infective endocarditis (heart valve infection), aortic dissection (tearing of the aorta), or chest trauma and generally requires immediate intervention.
Chronic aortic valve regurgitation can progress silently over many years. One of the most common causes is congenital bicuspid aortic valve (aortic valve with two leaflets instead of three). Additionally, rheumatic heart diseases, connective tissue diseases such as Marfan syndrome and Ehlers-Danlos syndrome, ankylosing spondylitis, syphilis, and uncontrolled hypertension can also cause aortic regurgitation.
The severity of aortic valve regurgitation is classified as mild, moderate, and severe based on the amount of blood that flows back. Mild regurgitation is usually asymptomatic and does not require treatment (but requires monitoring). Moderate regurgitation may require medication in some patients. Severe aortic regurgitation, especially if there are symptoms or left ventricular dysfunction, usually requires surgery or intervention.
In untreated severe aortic valve regurgitation, symptoms such as heart failure, cardiac arrhythmias, chest pain, and significant decrease in exercise capacity may occur. Severe aortic regurgitation left untreated for a long time may also carry a risk of sudden death.
What Causes Aortic Valve Disease?
Aortic valve disease can stem from many causes that affect the structure and function of the valve. The most common causes include age-related changes, congenital problems, infections, connective tissue diseases, and general health issues. These factors can disrupt the structure of the valve, leading to the development of stenosis or regurgitation.
Age-related changes are particularly the most common cause of aortic stenosis. As age advances, calcium accumulates in the aortic valve leaflets, leading to stiffening of the valve and reduction in its movement. This process can progress more rapidly if there are vascular stiffness risk factors such as high cholesterol, diabetes, hypertension, and smoking.
Congenital problems, especially bicuspid aortic valve (two leaflets instead of the normal three), increase the risk of aortic valve disease. Bicuspid aortic valve is the most common congenital heart problem seen in approximately 1-2% of the population and can predispose to aortic stenosis or regurgitation at an early age. More rarely, conditions such as unicuspid or quadricuspid aortic valve can also be observed.
Heart valve infection (infective endocarditis) is the inflammation and damage caused by bacteria or other microbes settling on the valve leaflets. This infection can lead to aortic regurgitation by causing holes, tears, or damage to the valve leaflets. It can also cause aortic stenosis by forming microbial clusters (vegetation) on the valve.
Rheumatic fever is a disease that develops after an infection caused by group A streptococcus bacteria and can damage heart valves. Rheumatic fever is one of the important causes of aortic valve disease, especially in developing countries. Defense substances (antibodies) formed during the infection damage heart tissue, causing inflammation, thickening, and adhesion of the valve leaflets.
Connective tissue diseases, especially genetic problems that affect the aortic root such as Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome, can lead to enlargement of the aorta and valve regurgitation. In these diseases, the aortic wall weakens and enlarges due to genetic disorders in the connective tissue, preventing the valve leaflets from closing completely.
General health problems, such as immune system diseases like ankylosing spondylitis, rheumatoid arthritis, and lupus, can cause inflammation and damage to heart valves. Additionally, conditions such as hypertension, aortic aneurysm, and aortic dissection can also lead to aortic root enlargement and valve regurgitation.
What are the Symptoms of Aortic Valve Disease?
The symptoms of aortic valve disease vary depending on the type of disease (stenosis or regurgitation), its severity, and how quickly it progresses. While there are generally no complaints in mild cases, as the disease progresses, the heart’s working capacity is affected, and symptoms emerge. Complaints seen in aortic stenosis and regurgitation may show some differences.
The most common symptoms in aortic stenosis are shortness of breath, chest pain, fainting or feeling like fainting, and inability to exercise. Shortness of breath occurs due to fluid accumulation in the lungs as a result of the heart’s difficulty in sending blood to the lungs. Chest pain develops due to the heart muscle’s increased oxygen need not being met. Fainting or feeling like fainting occurs because not enough blood can reach the brain during exercise. These complaints become more pronounced especially during exercise or physical activity.
Symptoms seen in aortic regurgitation include shortness of breath, palpitations, fatigue, and heart failure symptoms. People with slowly developing aortic regurgitation generally do not feel complaints for a long time. However, as the left ventricle begins to enlarge over time, symptoms begin. As heart failure progresses, shortness of breath increases especially when lying down or during exercise. Conditions such as waking up suddenly breathless at night, feeling shortness of breath when lying down, and swelling in the ankles (edema) may be observed.
In advanced aortic valve disease, general symptoms of heart failure such as fatigue, loss of appetite, weight loss, frequent urination at night, swelling, and loss of appetite may occur. Cardiac arrhythmia may also develop in those with aortic valve disease; in this case, palpitations, dizziness, and even fainting may be felt.
How is Aortic Valve Disease Treated?
The treatment of aortic valve disease is determined based on the type and severity of the disease, the presence of symptoms, and the patient’s general health condition. Treatment options include regular monitoring, medication therapy, surgery involving valve repair or replacement, and catheter-based interventions that have become widespread in recent years. The main goal of treatment is to alleviate symptoms, prevent complications, and improve quality of life.
Patients with mild aortic valve disease who have no symptoms generally do not require treatment, but it is important that they are regularly monitored. These individuals may be advised to use antibiotics in certain special situations (such as before dental procedures, in the presence of a prosthetic valve, or if they have had endocarditis in the past) to reduce the risk of heart valve infection (endocarditis). Additionally, healthy lifestyle changes (balanced diet, regular exercise, avoiding smoking and alcohol) are recommended. Controlling risk factors such as hypertension, diabetes, or high cholesterol may also slow the progression of the disease.
Medication therapy is generally used to reduce symptoms, lighten the heart’s load, and prevent complications. There is no medication that will widen the valve in those with aortic stenosis. However, diuretics, blood pressure-lowering medications, and heart rate-regulating medications may be used in patients who have developed heart failure. In those with aortic regurgitation, blood pressure-lowering medications can reduce the load on the left ventricle. Rhythm-regulating medications or blood thinners may be used in those with cardiac arrhythmia.
Surgery is generally the most effective treatment option for patients with aortic valve disease who have moderate to severe symptoms. Surgery can be in the form of repairing the valve (aortic valve repair) or replacing it (aortic valve replacement). Aortic valve repair can be applied in some patients with aortic regurgitation. If the valve structure is not suitable or repair is not possible, replacement is done with mechanical or biological prosthetic valves.
Mechanical valves are generally more durable and can be used for a lifetime but require blood-thinning medication. Biological valves do not require blood thinners but may need to be replaced within 10-15 years. The choice of valve is determined based on factors such as the patient’s age, general health condition, plans to have children, lifestyle, suitability for blood-thinning medication use, and the patient’s preference.
In recent years, transcatheter aortic valve replacement (TAVR or TAVI) has become increasingly widespread, especially in patients with high surgical risk. In this procedure, a new valve is placed inside the existing damaged valve with a catheter inserted through a blood vessel in the groin area. TAVR is a less invasive method as it does not require opening the breastbone, and the recovery period is shorter. While initially applied only in high-risk patients, today it can be preferred in some moderate and low-risk patients. However, not every patient may be suitable for this method, and this decision should be made by a heart team.
The treatment decision should be personalized according to the patient’s condition and evaluated by a team of specialists. The patient’s age, other diseases, severity of symptoms, degree of valve disease, and heart functions are important factors in the treatment decision.
Patients with aortic valve disease should also be regularly monitored after treatment. Regular check-ups are important, especially in patients who have undergone valve repair or replacement, to check the functioning of the prosthetic valve, adjust blood-thinning therapy, and for early diagnosis of possible problems. Additionally, good oral and dental health and the use of antibiotics before dental procedures and surgeries are recommended to reduce the risk of heart valve infection.
Reference: Aortic Valve Disease
