Background: The biochemical confirmation of myocardial infarction is based on cardiac troponin (cTnI or cTnT) determination. Recent scientific results suggested that microRNAs (miRNAs) might become a new biomarker of tissue injury.
Aim: To evaluate the release kinetics of circulating heart-specific miRNA-208a and also to test the hypothesis that miRNA-208a can serve as an accessible, diagnostically sensitive plasma biomarker of ST-elevation acute myocardial infarction (STEMI).
Methods: Nineteen STEMI patients (four women and 15 men, aged 44-85 years), 12 patients with stable coronary artery disease (CAD), and eight patients with a negative observation of CAD as a control group were studied. Blood samples were collected on admission and at three, six, 12, 24, and 48 h afterwards; in the CAD and control group blood samples were taken only once. Plasma levels of miRNA-208a determined by real-time polymerase chain reaction and their relative fold changes were calculated. cTnI and creatinine kinase (CK)-MB mass were also measured in the patients’ serum samples.
Results: miRNA-208a was increased in STEMI patients at the time of admission and nearly undetectable in CAD patients and controls. The peak of miRNA-208a was observed at 3 h after reperfusion (p < 0.001). The traditional biomarkers (cTnI and CK-MBmass), which increase later in comparison to miRNA-208a reaching the maximum concentrations 6 h after reperfusion, were observed. Circulating miRNA-208a levels strongly correlated with cTnI and CK-MBmass released from the infarcted area.
Conclusions: These results demonstrate that plasma miRNA-208a is an interesting and promising candidate for a new biomarker released early after onset of myocardial infarction.