Supravalvular aortic stenosis

The severity of supravalvular aortic stenosis varies from a mild narrowing above the aortic valve to a deformity which resembles an hour-glass.

Similar pathological changes are often seen throughout the large conducting arteries of the body, stenoses being found in the carotid, innominate and mesenteric arteries.

In common with all forms of aortic stenosis, there is hypertrophy of the left ventricle, but in this condition, the degree of enlargement seems out of proportion ot the degree of outflow obstruction.

The aortic stenosis is not congenital, but is acquired during early life as the result of an inherited arteriopathy.

NICE guidance states (1):

Consider referring adults with asymptomatic severe aortic stenosis for intervention, if suitable, if they have any of the following:

• Vmax (peak aortic jet velocity) more than 5 m/s on echocardiography
• aortic valve area less than 0.6 cm2 on echocardiography
• left ventricular ejection fraction (LVEF) less than 55%
• B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) level more than twice the upper limit of normal
• symptoms unmasked on exercise testing.

Consider referring adults with symptomatic low-gradient aortic stenosis with LVEF less than 50% for intervention if during dobutamine stress echocardiography the aortic stenosis is shown to be severe by:

• a mean gradient across the aortic valve that increases to more than 40 mmHg and
• an aortic valve area that remains less than 1 cm2.

Consider measuring aortic valve calcium score on cardiac CT if the severity of symptomatic aortic stenosis is uncertain.

Offer enhanced follow up (for example, more frequent reviews) and further assessment (for example, stress echocardiography) to monitor the need for intervention if mid-wall fibrosis is detected on cardiac MRI in adults with severe aortic stenosis.

Reference:

• NICE (November 2021). Heart valve disease presenting in adults: investigation and management