Abstract 1873: Occurrence and Progression of Supravalvar Aortic Stenosis in Adults
Background: Supravalvar aortic stenosis (SVAS) is a rare form of left ventricular outflow tract (LVOT) obstruction with a strong association to Williams syndrome (WS). In children, the disease is often progressive and may involve obstruction of coronary arteries. Little is known about outcome in adults.
Aim: To determine the occurrence and progression of SVAS in adults.
Methods: All adults (>18 years) with WS and/or SVAS (either operated or native) were identified from our clinic database. Clinical information, electrocardiographic, echocardiographic and magnetic resonance imaging studies were reviewed. SVAS was defined as morphologic narrowing of the ascending aorta, above the coronary arteries. The primary endpoint was de novo occurrence or progression of SVAS defined as an increase in peak systolic pressure gradient of ≥ 10 mmHg by Doppler echocardiography. Secondary endpoints were coronary events (myocardial infarction, stable or unstable angina pectoris or sudden cardiac death), dilatation of the ascending aorta at the site of previous repair, reoperation and death.
Patients and results: Fifty-two adults were identified; 34 (65%) had WS, and 13 (25%) had LVOT obstruction at multiple levels. Twenty-seven (52%) patients had undergone surgical repair of SVAS in childhood. At their first visit in adulthood 15 (29%) had SVAS (79% native SVAS, 21% residual SVAS after surgery). Mean follow up time was 7.5 +/− 6 years. Mean age at last follow up was 29 +/−9 years (range, 18 –58 years). No patients with SVAS at presentation to the adult clinic had progression of SVAS gradients as measured echocardiographically (mean peak systolic SVAS gradient at presentation 29 +/− 15 mmHg and at last follow up 29 +/− 15 mmHg, p = 0.9). No patients had de novo occurrence of SVAS in follow up. One patient died from severe mitral regurgitation and four underwent reoperation for aortic or pulmonary valve replacement, none for isolated SVAS. No patients developed aneurysmal dilatation of the ascending aorta at the site of previous surgical repair or had coronary events.
Conclusion: In this cohort, supravalvar aortic stenosis did not appear to occur de novo or progress in adult patients at risk. In adults, the progressive nature of this disease may be different from children.