Whether Circulating miRNAs or miRNA-Carriers Serve as Biomarkers for Acute Myocardial Infarction.

Acute myocardial infarction (AMI) remains a major cause of death in the US. An early and reliable diagnosis may warrant immediate initiation of reperfusion therapy to potentially improve the survival rate among the AMI patients. Currently, cardiac troponins (i.e. cTnT and cTnI) and creatine kinase MB (CK-MB) are widely used for AMI diagnosis. However, elevation of these biomarkers is also observed in human patients with myocarditis, aortic dissection, pulmonary embolism, congestive heart failure and renal failure. Furthermore, measurable amounts of troponin proteins are usually not released from damaged myocardium before 4 to 8 h after onset of symptoms, making an early biomarker-based diagnosis of AMI rather difficult. Therefore, new biomarkers with high sensitivity and specificity in early diagnosis of AMI are greatly needed.