Cardiovascular changes in children with mucopolysaccharide disorders

The aims of this study were to evaluate cardiac involvement, assess risk factors and mortality, and define the outcome of cardiac abnormalities with age in the different types of mucopolysaccharidoses (MPS). The echocardiograms of 99 patients with MPS, aged 1-24 y (median age 10.3 y) were reviewed between 1978 and 2000. Mitral regurgitation (MR) was detected in 29 patients (29%). MR was more frequent in types IH [n = 11 (38%)], II [n = 10 (24%)] and III [n = 4 (20%)]. Sixteen patients (16%) developed aortic regurgitation (AR), seen mostly in types II [n = 9 (56%)] and IV [n = 4 (24%)]. AR and/or MR was detected in 37 patients and 8 had both abnormalities of borderline significance (odds ratio 2.95, 95% confidence interval 1.0-8.85, p = 0.05). Of 99 patients, 47 had a normal study on their first echocardiogram, whereas only 7 had a normal study on subsequent echocardiograms. Fifty-four (54%) had a single echocardiogram. Of these, 27 (50%) were abnormal and 27 normal. Forty-five patients had more than one echocardiogram, of which 25 (56%) were abnormal and 20 normal. In 13/20 (65%) a cardiac abnormality developed on a subsequent echocardiogram which was statistically significant (p = 0.002). Overall mitral and aortic valve abnormalities showed a positive association with age. Univariate analysis of risk factors showed that increasing age, MPS I and ejection fraction were significant risk factors for death. However, left ventricular hypertrophy, mitral valve abnormalities and type II MPS were not significant risk factors for death, with borderline significance for aortic valve abnormalities.

This study demonstrates the evaluation of ventricular function, which is a significant risk factor for death, along with increasing age and MPS I, and outlines the borderline significance of aortic valve abnormalities, which has not been mentioned in previous studies. It also shows that mitral valve lesions, commonly seen in MPS, were not a significant risk factor for death. The results emphasize the importance of performing serial echocardiograms in patients with MPS to assess ventricular function and the progression of cardiac abnormalities with age.