The number of children suffering from cardiovascular diseases (CVDs) is rising globally. Therefore, there is an urgent need to acquire a better understanding of the genetic factors and molecular mechanisms related to the pathogenesis of CVDs in order to develop new prevention and treatment strategies for the future. MicroRNAs (miRNAs) constitute a class of small non-coding RNA fragments that range from 17 to 25 nucleotides in length and play an essential role in regulating gene expression, controlling an abundance of biological aspects of cell life, such as proliferation, differentiation, and apoptosis, thus affecting immune response, stem cell growth, ageing and haematopoiesis. In recent years, the concept of miRNAs as diagnostic markers allowing discrimination between healthy individuals and those affected by CVDs entered the purview of academic debate. In this review, we aimed to systematise available information regarding miRNAs associated with arrhythmias, cardiomyopathies, myocarditis and congenital heart diseases in children. We focused on the targeted genes and metabolic pathways influenced by those particular miRNAs, and finally, tried to determine the future of miRNAs as novel biomarkers of CVD.

Recent years have confirmed the importance of oxidative stress and biomarkers of inflammation in estimating the risk of cardiovascular disease (CVD) and explaining not fully understood pathogenesis of diabetic macroangiopathy. We aimed to analyze the relation between the intima-media thickness (IMT) of common carotid arteries and the occurrence of classical cardiovascular risk factors, together with the newly proposed biomarkers of CVD risk (high-sensitivity C-reactive protein (hsCRP), myeloperoxidase (MPO), adiponectin, N-terminal-pro B-type natriuretic peptide (NT-proBNP) and vitamin D) in youth with type 1 diabetes (T1D) recognized in screening tests to present early stages of microvascular complications (VC). The study group consisted of 50 adolescents and young adults with T1D, mean age 17.1 years (10–26 age range), including 20 patients with VC (+) and 30 VC (−). The control group (Control) consisted of 22 healthy volunteers, mean age 16.5 years (11–26 age range). In the VC (+) patients, we found a significantly higher concentration of HbA1c, lipid levels, hsCRP and NT-proBNP. BMI and blood pressure values were highest in the VC (+) group. Higher levels of MPO and lower levels of vitamin D were found in both diabetic groups vs. Control. IMT in VC (+) patients was significantly higher and correlated positively with HbA1c, hsCRP, NT-pro-BNP and negatively with vitamin D levels. In conclusion, youth with T1D and VC (+) present many abnormalities in the classical and new CVD biomarkers. hsCRP and MPO seem to be the most important markers for estimating the risk of macroangiopathy. NT-proBNP may present a possible marker of early myocardial injury in this population.