Release kinetics of circulating miRNA-208a in the early phase of myocardial infarction.

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.