Intro Cardiomyopathy is a common cause of morbidity and death in individuals with Duchenne muscular dystrophy (DMD). association between medical stage and cardiomyopathy SF or EF. Limiting the analysis to those not currently taking cardiac medications did not switch the interpretation of the association of cardiomyopathy with medical stage (data not shown). Discussion Results from the baseline data of cardiac disease in DMD from a multi-center multi-national natural history study demonstrate a significant disease burden from cardiomyopathy based on echocardiogram findings only. The mean age for development of cardiomyopathy of age 16.4 years was determined based on the age of the last COL5A2 recorded echocardiogram prior to enrollment. Previous studies showed a range of age groups from 13.2 to 14.1 years which was based on the age of 1st irregular echocardiogram.20 14 Nearly 15% of participants between ages 6 RAF265 (CHIR-265) and 13 years met criteria for cardiomyopathy and this increased to over 50% of participants more than age 14 years. Age was a significant predictor of cardiomyopathy and negatively correlated with EF and SF actions. Remarkably 32 of subjects enrolled in the CINRG DNHS did not report possessing a medical echocardiogram by the time of their 1st visit in the CINRG DNHS. Of these approximately one-third were 10 RAF265 (CHIR-265) years or older a cohort that shown a 34% prevalence of cardiomyopathy in those who did have an echocardiogram at baseline. Also concerning is that greater than half of the participants with cardiomyopathy reported no treatment with cardiac medications at baseline. Earlier studies support the restorative good thing about pharmacological treatment of cardiomyopathy in DMD individuals.10 21 20 24 Our findings suggest that under-treatment of cardiomyopathy in DMD could be a RAF265 (CHIR-265) significant cause of comorbidity. There is wide variability in past reports of the prevalence of cardiomyopathy using echocardiography in DMD individuals. The largest study correlating age with incidence and age of onset of cardiomyopathy was Nigro (2005) and Markham (2008) suggested a protective effect of GC treatment on development of cardiomyopathy.12 Our study showed that cardiomyopathy is associated significantly with clinical stage when later stages were compared with the earlier least symptomatic stage classified as early ambulatory. In particular the strongest association was observed by comparing the late non-ambulatory stage with the early ambulatory stage. Few studies statement both specific medical stage and cardiac data. Vehicle Brockel (2005) that also shown no significant correlation between cardiac involvement and GC therapy.28 25 However 2 recent studies demonstrate beneficial effects of GC therapy on cardiomyopathy. Barber et al. (2013) showed delayed onset of cardiomyopathy related to GC therapy.33 Schram et al. (2013) showed that GC therapy in addition to renin-angiotensin-aldosterone system antagonists significantly improved survival over a 15 yr follow-up period.34 Other series reported stabilization of cardiac function with exposure to GCs (prednisone and/or Deflazacort).35 11 13 31 12 Our analysis is limited by a relatively small number of GC na?ve participants (n=35). Longitudinal follow-up of this RAF265 (CHIR-265) RAF265 (CHIR-265) cohort may provide additional insights into any effect of GC therapy on cardiomyopathy. Interestingly we found that 12% of participants without evidence of cardiomyopathy were taking cardiac medications. This included 5 of 52 who were less than age 10 years and 10 of 75 who were greater than age 10 years. One previous study and the 10 yr follow up shown a beneficial effect of angiotensin transforming enzyme inhibitor therapy on cardiac function after 5 years and on mortality after 10 years.10 21 Some practitioners prescribe cardiac medications prior to the onset of cardiomyopathy; however dedication of the benefits of this practice requires further study. 36 There are some potential limitations to this study inherent in a natural history cohort. However these limitations are balanced from the inherent strength the cohort displays current medical management. We were unable to obtain a total dataset within the presence or absence of cardiomyopathy for those participants because not all participants had echocardiography results for a variety of reasons including: 1) young age at enrollment 2 like a function of the medical care received or 3).