O2052: Novel, Echocardiographic Indicators of Coronary Artery Stenosis in Williams Syndrome Are Comparable to Catheter Angiography

Background: The prevalence of coronary artery stenosis (CAS) is uncertain in Williams Syndrome (WS), but may occur in up to 27%. Assessing CAS is difficult and usually requires imaging while under general anesthesia. There is a 25 to 100-fold increased risk of sudden cardiac death in WS, most often occurring during anesthesia. Through a large clinical experience with WS, we have identified multiple novel echocardiographic indicators that seem to identify the presence of CAS. We sought to investigate those indicators.

Methods: We performed a single-center retrospective study of all children with WS that underwent intraoperative assessment for CAS from January 1, 2006 to April 30, 2021. In addition to using the operative assessment for CAS as the gold standard, we compared the novel echocardiographic indicators to catheterization angiography. Those with prior coronary artery interventions were excluded. All relevant clinical data were collected. Two blinded investigators with advanced training in echocardiography reviewed the immediate preoperative echocardiograms for each patient. Two blinded investigators with advanced training in interventional catheterization reviewed the preoperative catheterization images. Kappa coefficient and Bland-Altman analysis were used to determine interrater reliability. Wilcoxon rank-sum and Fisher’s exact test were used to compare the numerical and categorical variables of each diagnostic test.

Results: We included 34 patients (62% male) with a median age of 20 months [IQR: 8, 34]. CAS was present in 62% (21/34). Those with CAS were younger (13 months [6, 26] vs. 25 months [18, 68], p=0.036) and weighed less (7.7 Kg [5.6, 9.6] vs. 11 Kg [7.9, 19.3], p=0.037). The Tables present the comparisons of study measurements between those with and without CAS. Multiple echocardiographic indicators were present in those with CAS. The concomitant presence of left ventricular hypertrophy and a coronary artery origin above the sinotubular junction were highly predictive of CAS. The sensitivities of the novel echocardiographic indicators were non-inferior to those of catheterization angiography.

Conclusion: Our novel echocardiographic indicators are comparable to catheterization angiography for making the diagnosis of CAS. In the face of the high risk of anesthesia-related cardiac arrest in WS, our echocardiographic parameters provide an anesthetic-free means of identifying CAS in WS. These markers should be evaluated in all children with WS.