Abstract 15361: Comparison of Cardiovascular Outcomes of Supravalvar Aortic Stenosis Patients With Williams Syndrome and Non-williams Supravalvular Aortic Stenosis

Introduction: Cardiovascular outcomes in Williams syndrome (WS) with supravalvar aortic stenosis (SVAS) compared to those with non-Williams SVAS (NW-SVAS) have not been well-described in literature. Hypothesis: Cardiovascular outcomes are similar in SVAS patients in WS and those with NW-SVAS as both are typically mediated by elastin ( ELN ) deficiency. Methods: We included all patients (pts) at our institution with 1) WS and SVAS or 2) SVAS with negative testing for WS (2003-2020), excluding pts with Alagille or Turner syndrome, isolated bicuspid aortic valve, postoperative acquired SVAS, or insufficient records. We compared cardiovascular lesions and freedom from intervention using Kaplan-Meier analysis with comparison by log rank. Results: Of 163 included SVAS pts (67 WS, 96 NW-SVAS), 75 (46%) were females. Median age at last follow up was 11.9 years (IQR 5.7, 17). Of ELN testing performed in 13 NW-SVAS patients, 8 had pathogenic variants. The rest of the NW-SVAS cohort included 22 familial and 61 non-familial cases. Branch pulmonary artery stenosis (BPAS), renal artery stenosis (RAS), and hypertension were more prevalent in WS than in NW-SVAS (p=0.001, Table). There was no difference in freedom from BPAS intervention between the groups, but the WS group was significantly more likely to undergo intervention for RAS or be treated for hypertension (Figure). No difference was noted for SVAS, coarctation or coronary outcomes. Conclusion: For most cardiovascular lesions, there was no difference in interventions between WS and NW-SVAS. The increased intervention rate for RAS and hypertension in WS may reflect lower screening rates in NW-SVAS

MRI detection of occult venous anomalies in a patient with Williams syndrome: a case report

Williams syndrome is a multisystem, congenital disorder which is commonly associated with arterial stenoses: supravalvar aortic stenosis and peripheral pulmonary artery stenosis. Venous abnormalities have not been previously reported in children with Williams syndrome. We present a case of a 3-year-old girl with Williams syndrome and diffuse venous ectasia as detected by MRI.