First manifestation and evolution of early left ventricular dysfunction in children with Duchenne muscular dystrophy

Background: Standard pediatric cardiology examinations and echocardiography fail to discover when the cardiomyopathy will occur in patient with Duchenne muscular dystrophy (DMD). Noninvasive markers are needed to fill this gap. Material and methods: This cohort study included a total number of 30 children (21 children (70%) with DMD and 9 (30%) healthy children. Blood samples were used for biochemical (level of creatine kinase, creatine kinase-MB, lactate dehydrogenase) and miRNA (presence of miR133a 3p, miR133b 3p, miR206 3p, miR208a 3p, miR208b 3p) analysis. All patients underwent partial conventional echocardiography ECOCG and Speckle Tracking. Results: The children in the working group presented compared to healthy children: FCC values increased by 15 (71%) vs 2 (22%), high levels of CK, CK-MB, LDH, which is characteristic for the disease and reflects its stage. Also, there is a decrease in systolic function indicators in the working group: mean FE 59 ± 3.8 %, and GLS: -16.2 ± 3.1%. MiRNA analyses confirmed the presence of miR133a 3p, miR133b 3p, miR206 3p, miR208a 3p, miR208b 3p in both working and control group. Conclusions: For the first time in the Republic of Moldova, we developed and adapted protocols for RNA extraction from human blood, performing screening of specific miRNA in the serum of patients with DMD and healthy children. Also, altered LV strain notwithstanding a normal or mildly modified LVEF represents an essential viewpoint for prospective pediatric drug trials in DMD-related cardiomyopathy prevention.