Exosomal miRNA‐21‐5p and miRNA‐21‐3p as key biomarkers of myocardial infarction

Objective Coronary artery disease (CAD) is a debilitating condition that can lead to myocardial infarction (MI). Exosomal miRNAs (exo‐miRNA) can be diagnostic biomarkers for detecting MI. Here, we conduct a study to evaluate the efficacy of exo‐miRNA‐21‐5p/3p for early detection of MI. Methods A total of 135 CAD patients and 150 healthy subjects participated in this study. Additionally, we randomly divided 26 male Wistar rats (12 weeks old) into two groups: control and induced MI. Angiographic images were used to identify patients and healthy individuals of all genders. In the following, serum exosomes were obtained, and exo‐miRNA‐21‐5p/3p was measured by reverse‐transcriptase polymerase chain reaction. Results We observed an upregulation of exo‐miRNA‐21‐5p/3p in CAD patient and MI‐induced animal groups compared to controls. Analysis of the ROC curves defined 82% and 88% of the participants' exo‐miRNA‐21‐5p and exo‐miRNA‐21‐3p diagnostic power, respectively, which in the animal model was 92 and 82. Conclusion This study revealed that the mean expression levels of exo‐miRNA‐21‐5p/3p were significantly increased in CAD patients and animal models of induced MI. Also, these results are associated with the atherogenic lipid profile of CAD patients, which may play an important role in the progression of the disease. Therefore, they can be considered as novel biomarkers.