Abstract 4139907: Evaluating the Associations Between Medications and Cusp Fusion Patterns on Aortic Growth in Children with Bicuspid Aortic Valve

Background: Children with bicuspid aortic valve (BAV) often have progressive aortic dilation, conferring an increased risk of dissection in adulthood. Data describing medication use in aortic dilation in children with BAV are limited. This study aims to evaluate longitudinal trends of aortic growth, comparing those on angiotensin receptor blockers (ARBs) or beta-blockers (BBs) to no medical therapy. Methods: This retrospective cohort included subjects with BAV with first echo <18 years from 2010-2023 with > 1 echocardiogram with root or ascending z-score > 3.5 and > 2 available echocardiograms. The primary exposure was medication status, stratified as none, ARB, or BB. Outcomes evaluated were trends in 1) ascending aortic (AscAo) z-score and 2) aortic root z-scores over time using multivariable mixed-effects linear regression to account for changing medication regimens over time. Results: In total, 115 patients (76% male) were included; 61 patients (53%) were treated at some point during the period of interest (17% ever on ARBs, 27% on BBs, and 9% on dual therapy). Regarding clinical features, for AscAo z-scores, only lower baseline AscAo z-score was associated with higher rate of growth; sex and cusp fusion type were not. On multivariable analyses controlling for baseline z-score, AscAo z-score decreased in patients on BBs relative to those not on medication (relative difference -0.1 + 0.03 z/year, p:<0.0001, Figure). For root z-score, lower baseline z-score was again associated with faster growth. Right-left fusion was also associated with increased change in root z-score compared to unicuspid valves (relative change +0.09, p=0.027 respectively); sex was not associated. In multivariable analysis controlling for baseline root z-score BBs and cusp fusion type, there was no difference in root-z-score change by medication (Figure). Conclusions: In this cohort of children with BAV and aortic dilation with z-score > 3.5, BB use was associated with a reduction in the ascending aorta z-score relative to patients not on medications. To date this is the largest study comparing change in aortic dimensions by medication class in children with BAV.