Increased plasma levels of hsa-miR-21-5p in patients with reduced left ventricle ejection fraction admitted urgently due to acute coronary syndrome

Myocardial ischemia that occurs during acute coronary syndrome (ACS) induces a cascade of pathophysiological processes which might lead to left ventricle dysfunction reflected by decreased left ventricular ejection fraction (LVEF) in echocardiographic examination. The enzymes regulating extracellular matrix (ECM) like matrix metalloproteinase 9 (MMP-9) also take part in this process. The MMP-9 activity is under control of a microRNA particle miR-21, which down-regulates its inhibitors. The study has shown, that in ACS population (n = 26) patients with LVEF < 50% presented increased miR-21 relative expression levels comparing to patients with LVEF ≥50% (3,33 vs 1,64; p = 0,015). Moreover, a significant negative correlation between LVEF and miR-21 in this group of patients has also been presented.