Aortic Root Dilatation in Mucopolysaccharidosis I–VII

The prevalence of aortic root dilatation (ARD) in mucopolysaccharidosis (MPS) is not well documented. We investigated aortic root measurements in 34 MPS patients at the Children's Hospital of Orange County (CHOC). The diagnosis, treatment status, age, gender, height, weight and aortic root parameters (aortic valve annulus (AVA), sinuses of Valsalva (SoV), and sinotubular junction (STJ)) were extracted by retrospective chart review and echocardiographic measurements. Descriptive statistics, ANOVA, and paired post-hoc t-tests were used to summarize the aortic dimensions. Exact binomial 95% confidence intervals (CIs) were constructed for ARD, defined as a z-score greater than 2 at the SoV. The patient age ranged from 3.4-25.9 years (mean 13.3 ± 6.1), the height from 0.87-1.62 meters (mean 1.24 ± 0.21), and the weight from 14.1-84.5 kg (mean 34.4 ± 18.0). The prevalence of dilation at the AVA was 41% (14/34; 95% CI: 25%-59%); at the SoV was 35% (12/34; 95% CI: 20%-54%); and at the STJ was 30% (9/30; 95% CI: 15%-49%). The highest prevalence of ARD was in MPS IVa (87.5%). There was no significant difference between mean z-scores of MPS patients who received treatment with hematopoietic stem cell transplantation (HSCT) or enzyme replacement therapy (ERT) vs. untreated MPS patients at the AVA (z = 1.9 ± 2.5 vs. z = 1.5 ± 2.4; p = 0.62), SoV (z = 1.2 ± 1.6 vs. z = 1.3 ± 2.2; p = 0.79), or STJ (z = 1.0 ± 1.8 vs. z = 1.2 ± 1.6; p = 0.83). The prevalence of ARD was 35% in our cohort of MPS I-VII patients. Thus, we recommend screening for ARD on a routine basis in this patient population.