Severe Aortic Stenosis
Patients with severe aortic valvular stenosis who have symptoms, such as effort angina, effort syncope, and heart failure have a very poor prognosis. Without intervention, death usually occur within a few years. The treatment is to relieve the obstruction.
An asymptomatic adult with aortic stenosis should undergo valve replacement if one of the following is present: left ventricular systolic dysfunction, abnormal response to exercise (e.g., hypotension), ventricular tachycardia.
In low gradient AS, when cardiac output is decreased, the gradient across the aortic valve is also decreased and estimated aortic valve area may be significantly decreased. In a patient with an aortic ejection murmur and a dilated left ventricle, these findings may represent a pseudostenosis due to a primary dilated cardiomyopathy or a patient with true severe aortic stenosis with markedly depressed ventricular contractility.
Differentiation of these diagnoses often requires further echocardiographic or catheterization testing, usually with dobutamine to increase left ventricular contractility. With pseudostenosis, no significant gradient will be present, and the aortic valve area will usually increase. With true severe stenosis, the gradient will increase with no increase in aortic valve area.
Several choices exist for surgical valve replacement. These include mechanical prosthesis, bioprosthesis, including homograft and heterograft, and autologous transfer of the patient’s pulmonary artery and valve to the aortic position – Ross procedure. Trans-catheter aortic valve replacement (TAVR) can be offered to some patients who are high-risk surgical candidates. Choice of treatment must be individualized.