Aortic stenosis occurs when the aortic valve in the heart is stiffened by calcium deposits. The result is a narrowing of the opening through which the heart pumps blood into the aorta, the large artery that carries blood to the rest of the body. Aortic stenosis is now the most common heart valve abnormality in the U.S.
The narrowed opening makes the heart work harder to pump blood and limits the blood supply to vital organs, particularly the heart and brain. Many people with aortic stenosis have no symptoms, but the disorder can often be detected with a chest X-ray or an ultrasound exam of the heart (echocardiogram). As the narrowing worsens, patients are likely to develop heart failure, angina (chest pain), and episodic loss of consciousness (syncope).
The development of severe symptoms in patients with aortic stenosis is life-threatening, and the only cure is surgical replacement of the abnormal valve. Surgery can effectively relieve the symptoms of aortic stenosis even when people are in their 80s.
An inherited abnormality of the valve resulting in two (rather than the normal three) leaflets is the most common cause of aortic stenosis in young people. In older individuals inflammation and collections of cholesterol in the valve precede the deposition of calcium. These changes in the aortic valve resemble the process of atherosclerosis in coronary arteries. Risk factors for coronary disease, such as high blood cholesterol levels and high blood pressure, are also common in people with aortic stenosis.
Because of the similarity between atherosclerosis and aortic stenosis, several research teams have studied the effects of lowering blood cholesterol on aortic stenosis. These studies showed that treatment with cholesterol-lowering statin drugs slowed the progression of aortic stenosis. So taking a statin to prevent coronary disease may have the additional benefit of preventing severe aortic stenosis.