160 DIFFUSE FIBROSIS IN ALSTRöM SYNDROME: A MARKER OF DISEASE PROGRESSION

Background Alström syndrome (ALMS) is a rare autosomal recessive genetic disorder with progressive multi-system involvement including; endocrine disarray, sensorineural deficit, cardiac, renal, and hepatic abnormalities. Idiopathic dilated cardiomyopathy (CM) is a major cause of morbidity and mortality. It is observed acutely in infancy in approximately 45% of individuals with high rates of recurrence and new cases in adulthood. Myocardial fibrosis has been demonstrated at post-mortem and on MRI with patchy diffuse late gadolinium enhancement (LE) in an older cohort of ALMS patients. We hypothesise that subclinical diffuse fibrosis in young patients with ALMS precedes any change in conventional parameters of ventricular function or overt scarring on LE. Methods Ten patients with ALMS (mean age 30±11 years, 70% male, 24 h ABPM 135±13/84±9 mm Hg) were compared to 10 newly diagnosed borderline hypertensive patients (mean age 42 years, 70% male, 24 h ABPM 134±8/84±8 mm Hg) and 10 gender matched healthy volunteers. All subjects underwent cardiac MRI (1.5T). Myocardial extracellular volume (ECV) was assessed using T1-mapping pre and 15 min post gadolinium (0.1 mmol/kg) using a modified look-locker inversion recovery sequence (MOLLI). Late gadolinium images were acquired 5–7 min after contrast. Myocardial T1 was assessed by manual contouring of the basal and mid interventricular septum, avoiding areas of LE from a four chamber view. Results Females in all three groups had significantly increased septal myocardial ECV compared with males (0.29±0.03 vs 0.25±0.03, p