Abstract 18473: Rates and Risk Factors for Faster Aortic Root Growth in Pediatric Patients with Marfan Syndrome

Abstract

Background: Marfan Syndrome (MS) is associated with progressive aortic dilation and aortic dissection. Aortic dissection is typically preceded by aortic dilation. The goal of this study is to identify factors associated with faster rates of aortic root dilation in children with MS. Methods: Patients undergoing serial transthoracic echocardiograms (TTE) with MS were retrospectively identified from an institutional database. Those with >2 TTEs over 1 year apart and <21 years of age at first TTE were included. TTEs performed after aortic surgery were excluded. Using multivariable longitudinal linear regression analysis, sex, medication, presence of ectopia lentis, need for scoliosis surgery and infantile type of MS were evaluated for associations with rate of change in aortic root dimension and aortic root z-score over time. Results: Of 240 patients with MS, 146 were included. Median age at first TTE was 8.1 yrs (range 0-20.9 years), median length of follow up 6.5 years (range 1.0-20.1 years), and median number of studies was 8 (range 2-25). Sixty-one percent were male. Of the 146 patients, 123 (84%) were documented to be on medical therapy: 14 angiotensin receptor blocker (ARB), 66 B-Blocker (BB), 10 prior history of both, 5 BB+ARB, 27 were in the Pediatric Heart Network medication trial, 1 ACE inhibitor. Sixteen patients underwent root replacement surgery at a median age of 14.6 years (range 1.8-24). No patients had aortic dissection. Three patients had infantile MS. All of these patients underwent root replacement at 1.8, 2 and 4 years of age. Two underwent subsequent aortic root replacement at 6 and 8 years old. Mean rate of aortic root growth in the cohort was 0.12cm/year, and mean change in z-score was 0.02/year (p=0.23 compared to expected rate of no change). The only variable associated with faster root growth was infantile MS (1.3cm/year, p<0.001; z-score change of 6.9/year, p<0.001). There was no significant difference in the rate of aortic root growth between patients who received therapy with BB vs. ARB vs. BB+ARB. Conclusions: Children with MS did not have a significant change in aortic root z-score over time, and the only factor associated with more rapid aortic root growth was infantile type MS.