Abstract: Objective To identify diagnostic biomarkers of plasma extracellular vesicle microRNAs(EV-miRNAs)for acute myocardial infarction(AMI)and to investigate their clinical diagnostic significance. Methods Plasma samples were obtained from three AMI patients and three healthy controls.miRNAs were extracted from both plasma and extracellular vesicles and subsequently subjected to sequencing to establish EV-miRNA profiles.Bioinformatics analysis was performed to select EV-miRNAs significantly associated with AMI.Validation plasma samples were collected from 27 AMI patients and 25 healthy controls for qRT-PCR analysis of the screened differentially expressed EV-miRNAs.The diagnostic performance of AMI-predictive EV-miRNAs was evaluated using ROC curve analysis.Target genes of the selected miRNAs were correlated with clinical indicators. Results Compared with the healthy control group,the expression levels of miR-6809-3p,miR-3938,miR-6815-5p,miR-4322,miR-6717-5p,and miR-6797-5p were significantly elevated in peripheral blood extracellular vesicles of the AMI group(all P<0.05).The area under the ROC curve(AUC)for miR-6815-5p,miR-4322,and miR-6717-5p exceeded 0.9,indicating high diagnostic potential.Furthermore,the expression of creatine kinase MB isoenzyme exhibited a weak positive correlation with miRNA-4322. Conclusion Plasma extracellular vesicle miRNAs may serve as potential molecular biomarkers for AMI diagnosis,providing novel insights for the identification of therapeutic molecular targets for AMI.

Key words: acute myocardial infarction, extracellular vesicles, miRNA, biomarker