Abstract 18498: Description of Aortic Root Growth and Outcomes in a Cohort of Pediatric Patients with Loeys-Dietz Syndrome

Abstract

Background: Loeys Dietz Syndrome (LDS) is associated with rapid aortic dilation and aortic dissection, but data on children with LDS are limited. The goal of this study is to describe aortic root growth and outcomes in children with LDS. Methods: Patients with LDS were identified from an institutional database. Data regarding genetic mutation, medications, aortic root dimensions by transthoracic echocardiography (TTE), aortic dissection and surgical intervention were collected. For those with >2 TTEs 1 year apart, rate of change in z-score was calculated using linear regression. TTEs performed after aortic surgery were excluded. We examined if variables were associated with rate of aortic root growth. Results: Of 16 patients, 8 were female. Five had a TGFBR1 and 9 had a TGFBR2 mutation; 2 patients did not have genetic data available. Median aortic root Z-score at diagnosis was 3.5 (range 0.5-25.4). Fifteen patients were on medication (2 beta-blocker (BB), 5 angiotensin receptor blocker (ARB), 5 BB+ARB, and 3 with past use of both). Four patients underwent prophylactic root replacement at ages 3.3, 6.7, 8.7, and 9.4 years at root dimensions 3.2, 6.5, 4.0, and 4.1 cm respectively. One patient had a Type A dissection at age 15y after prior root replacement and underwent repeat surgery. Another underwent heart transplant at 6.9 years old after prior root replacement. Ten patients had serial TTE data. Median change in aortic root diameter and Z-score was 0.11cm/year and 0.1/year respectively. Mean change in z-score per year for those on on BB was -0.1± (range -1.2 to 0.7), ARB 0.5 (range 0.1 to 1.1) and both 0.0 (range -0.2 to 0.2, p=NS). No variables studied were associated with faster aortic growth. Conclusions: Degree of aortic root dilation and rate of aortic root growth is highly variable in children with LDS, although factors associated more aggressive disease are unclear. The high proportion of patients with adverse outcomes including aortic dissection and surgery is concerning.