MR-based analysis of regional cardiac function in relation to cellular integrity in Fabry disease

Background Fabry cardiomyopathy is characterized by left ventricular (LV) hypertrophy and regional fibrosis. Recent high-end echocardiography studies of selected LV sections suggest an interrelation between regional fibrosis, impaired function, and hypertrophy possibly changing under specific enzyme replacement therapy (ERT). Methods Magnetic resonance imaging (MRI) was used for a region dependent study of cardiac function, morphology and late enhancement (LE) in 25 Fabry patients before and after 12months of ERT in comparison to 43 healthy volunteers. Results Fabry patients presented with LV increased wall thickness (EDWT) and reduced wall thickening (WT) with a focus on basal and midventricular regions corresponding to areas of LE. The degree of hypertrophy and hypokinesia were the highest if LE was detectable. A significant decrease of the EDWT under ERT was observed in LE negative patients accompanied by a decline of hypokinesia with regional differences. Conclusions Regional differences of LV hypertrophy and wall motion were detected corresponding to the distribution of myocardial fibrosis (LE). Functional impairment was closely restricted to fibrotic regions while morphologic changes slightly exceeded the areas of fibrosis. ERT resulted in regional improvements whereby absence of fibrosis was connected to a better outcome.