Peripheral Blood MicroRNAs as Potential Biomarkers of Myocardial Damage in Acute Viral Myocarditis.

Background: microRNAs (miRs) have emerged as important modulators of cardiovascular development and disease. Our aim was to determine whether cardiac-related miRs such as miR-21-5p and miR-1-3p were differentially expressed in acute viral myocarditis and whether any of them was related with the extent of myocardial damage and left ventricular dysfunction. Methods: We enrolled 40 patients with acute viral myocarditis. Blood samples were taken on admission and miRs expression levels in peripheral blood mononuclear cells were quantified by real-time reverse transcription polymerase chain reaction. Results: miR-21-5p, miR-1-3p were significantly elevated in acute myocarditis. miR-21-5p levels showed a strong correlation with global longitudinal strain (r = 0.71, p < 0.01), while miR-1-3p had significant correlations with troponin I (r = 0.79, p < 0.01). Conclusions: The expression of miR-21-5p and miR-1-3p in peripheral blood is increased in acute viral myocarditis, and this increase is correlated with myocardial damage and indicative of left ventricular systolic dysfunction in these patients.