miRNA in peripheral and coronary serum of CAD and acute MI patients

Background: We aimed to identify circulating miRNA associated with chronic coronary artery disease (CAD) and myocardial infarction (MI) in peripheral blood vessels and coronary arteries proximal to an occluded culprit area. Methods: Patients having chronic CAD, acute MI either with or without ST segment elevation (STEMI and NSTEMI, respectively), and control patients with no previous or current CAD, were recruited to the study. Blood samples were collected during coronary catheterization procedure from the peripheral and from the culprit coronary artery. Serum miRNA was sequenced, and miRNA identified as differentially expressed was validated by quantitative-real-time PCR. Results: Sequencing analysis revealed miR-483-5p as differentially expressed in STEMI patients versus controls. Further qPCR experiment demonstrated a significant downregulation of miR-483-5p in peripheral samples of CAD and MI patients compared with controls (1.1 vs.2.6, respectively). In coronary samples, miR-483-5p was reduced only in chronic CAD, whereas its expression in MI patients was similar to controls. A ROC analysis for association of peripheral serum miR-483-5p with chronic CAD demonstrated an area under the curve of 0.722. Conclusion: miR-483-5p is differentially expressed in chronic CAD and MI and has local effects in culprit artery, suggesting it as an important player in CAD and a potential biomarker.