Aortic stenosis occurs when the heart’s aortic valve narrows. This narrowing prevents the valve from opening fully, which reduces or blocks blood flow from your heart into the main artery of your body (aorta). When the blood flow through the aortic valve is reduced, your heart needs to work harder to pump blood to your body. Eventually, this extra work limits the amount of blood it can pump, and this can cause symptoms as well as possibly weaken your heart muscle. Left untreated, aortic valve stenosis can lead to serious heart problems. Aortic stenosis is a life-threatening condition that is present in more than 3 percent of the population. The average age at presentation is 75 years old.
Causes of Aortic Stenosis
Aortic stenosis can occur due to many causes, including congenital heart defect (a condition that is present at birth) such as a bicuspid aortic valve, calcium buildup on the valve, or rheumatic fever (a complication of strep throat infection in which scar tissue can form on the aortic valve). The risk factors of aortic valve stenosis include older age, certain heart conditions present at birth (congenital heart disease) such as a bicuspid aortic valve, history of infections that can affect the heart, having cardiovascular risk factors, such as diabetes, high cholesterol and high blood pressure, chronic kidney disease, and history of radiation therapy to the chest.
Signs and Symptoms
Aortic valve stenosis ranges from mild to severe. Aortic valve stenosis signs and symptoms generally develop when narrowing of the valve is severe. Some people with aortic valve stenosis may not experience symptoms for many years. The classic signs and symptoms of aortic valve stenosis include chest pain, shortness of breath and feeling faint or dizzy with activity (syncope). An abnormal heart sound (heart murmur) can also be heard through a stethoscope.
Diangosing Aortic Stenosis
To diagnose aortic valve stenosis, your doctor may review your signs and symptoms, discuss your medical history, and conduct a physical examination. Your doctor may listen to your heart with a stethoscope to determine if you have a heart murmur that may indicate an aortic valve condition. Tests may include an echocardiogram which uses sound waves to produce video images of your heart in motion. This test can help doctors closely look at the condition of the aortic valve, and the cause and severity of your condition. Other tests that may be utilized include an electrocardiogram (EKG), chest X-ray, exercise tests or stress tests, cardiac computerized tomography (CT), cardiac MRI, and a cardiac catheterization.
How Aoritc Valve Stenosis is Treated
Treatment for aortic valve stenosis depends on the severity of your condition, whether you’re experiencing signs and symptoms, and if your condition is getting worse.
If your symptoms are mild or you aren’t experiencing symptoms, your doctor may monitor your condition with regular follow-up appointments. You may eventually need surgery to replace the diseased aortic valve. In some cases, your doctor may recommend surgery even if you aren’t experiencing symptoms.
Balloon Aortic Valvuloplasty (BAV)
Interventional cardiologists may conduct a procedure to dilate the narrowed aortic valve. In this procedure, called balloon aortic valvuloplasty, the interventional cardiologist inserts a catheter with a balloon on the tip into an artery in your arm or groin and guides it to the aortic valve. The balloon is then inflated expanding the opening of the valve. The balloon is then deflated, and the catheter and balloon are removed. The procedure is performed in adults who are too ill for surgery or who are waiting for a valve replacement. This procedure is not a permanent solution as the valve generally narrows back over the following six months.
Surgical Aortic Valve Replacement (SAVR)
Aortic valve replacement is often needed to treat severe symptomatic aortic valve stenosis. In aortic valve replacement, the cardiac surgeon removes the damaged valve and replaces it with a mechanical valve or a valve made from cow or pig tissue (biological tissue valve).
Biological tissue valves may degenerate over time and may eventually need to be replaced. People with mechanical valves will need to take blood-thinning medications for life to prevent blood clots. Your doctor will discuss with you the benefits and risks of each type of valve and discuss which valve may be appropriate for you.
Transcatheter Aortic Valve Replacement (TAVR)
Interventional cardiologists trained in structural heart disease intervention may perform a less invasive procedure called transcatheter aortic valve replacement (TAVR) to replace a narrowed aortic valve. TAVR may be an option for people who are considered to be at intermediate, high or extreme risk of complications from surgical aortic valve replacement.
In TAVR, the interventional cardiologist inserts a catheter in your leg, arm or chest. A replacement valve is then inserted through the catheter and guided to your heart. A balloon may expand the valve, or some valves can self-expand. When the valve is implanted, the catheter is removed from your blood vessel. Interventional cardiologists may also conduct a catheter procedure to insert a replacement valve into a failing biological tissue valve that is no longer working properly.
Since the average age of presentation for aortic stenosis is 75 years old, patients often have comorbidities that prevent them from tolerating surgical therapies. Therefore, much of the focus on treatment of aortic valve disease and aortic stenosis has moved to minimally invasive therapy such as TAVR, in which recovery is faster. Over the last decade, transcatheter aortic valve replacement has undergone a tremendous evolution. Studies have resulted in FDA approval of TAVR for intermediate, high and extreme risk patients. Studies are ongoing to evaluate the valve in low risk patients as well.
Today, TAVR has become an important option for patients with aortic stenosis. The newer generation of TAVR devices are much smaller. Procedures are performed while patients are awake. The rates of major complications are much lower. Hospital stays are only one to two days and recovery is much quicker than with open heart surgery. As the aging population grows, TAVR has become an excellent minimally invasive option for patients with aortic stenosis.