Expression of MicroRNA-133a and MicroRNA-208b in Egyptian STEMI Patients

Background: Myocardial microRNAs (Myo-miRs), such as miR-133 and miR-208, are specific to cardiac muscle development and function and are reported to increase after 14 hours of myocardial infarction. Early diagnostic potential of miRs in the acute episode of MI with ST-segment elevation (STEMI) is unknown. This study aimed to compare the fold changes in the peak time points of miRNAs in STEMI patients and compare them with the conventional markers; troponin I (TnI) and creatine kinase-MB (CK-MB). Methods: Ten patients with new-onset episodes of STEMI and 10 healthy subjects were recruited for the study. Blood samples were collected following the onset of chest pain at 04, 08, 12, 24 and 48 hours, and the serum was separated to determine the levels of circulating miR-133 and miR-208 via quantitative PCR (qPCR) and the cardiac enzymes TnI and CK-MB. Results: MiR-133a peaks at 8 hours, and miR-208b peaks at 12 hours from the onset of STEMI chest pain. In general, for both miRs, there was a significant difference between patients and healthy subjects. Conclusions: Compared with TnI and CK-MB, miR-133a and miR-208b have good early diagnostic specificity during the first 4–12 hours for STEMI.