Enzyme Replacement Therapy Decreases Left Ventricular Mass Index in Patients with Hunter Syndrome?

Although enzyme replacement therapy (ERT) has shown benefit in improving cardiac systolic function in a murine model of cardiomyopathy associated with Hunter syndrome, few studies have analyzed its effect in humans. We evaluated the effect of ERT on patients with Hunter syndrome-related cardiomyopathy. We performed a retrospective analysis of serial transthoracic echocardiograms performed before and over the first 5 years after treatment initiation, in 14 patients with Hunter syndrome. An important cardiac remodeling occurred in all patients in this study. There was a significant reduction in left ventricular mass index from 70.88 to 26.75 g/m^2.7 (p = 0.003), with a trend towards a decrease in relative wall thickness from 0.515 at baseline to 0.370 after 5 years of enzyme therapy (p = 0.140). No differences were observed in aortic root diameter, left atrial diameter, left ventricular diastolic and systolic diameters, left ventricular ejection fraction, or myocardial performance index. Our findings demonstrate that ERT contributes to reducing left ventricular mass index in patients with Hunter syndrome.