Circulating plasma microRNA expression in early-onset and late-onset coronary artery disease patients

The prevalence of coronary artery disease (CAD) is increasing among young adults. To improve CAD diagnosis, microRNAs are being explored as potential minimally invasive biomarkers. The aim of this study was to evaluate circulating microRNA (miRNA) expression profiles and assess their value in predicting the development of early-onset CAD. A total of 108 patients with early- and late-onset CAD and 29 individuals without CAD were included, and their miRNA expression was evaluated. The diagnostic value of differentially expressed miRNAs across the subgroups was tested by logistic regression models and ROC curve analysis. A total of 287 different circulating miRNAs were analysed following sequencing and preprocessing. Seven miRNAs (miR-10b-5p, miR-29c-3p, miR-142-5p, miR-320b, miR-451a, miR-486-3p, and miR-625-3p) were found to be differentially expressed across all the study groups, four of which (miR-142-5p, miR-29c-3p, miR-451a, and miR-486-3p) were significantly downregulated in the late-onset CAD group compared with the control group. ROC analysis demonstrated that the combination of the seven miRNAs had high diagnostic accuracy, with an AUC of 0.9924 for distinguishing late-onset CAD from the other groups, and moderate accuracy, with an AUC of 0.8235 for distinguishing early-onset CAD from the other groups. A combination of seven circulating miRNAs (miR-10b-5p, miR-29c-3p, miR-142-5p, miR-320b, miR-451a, miR-486-3p, and miR-625-3p) is a promising biomarker panel for CAD diagnosis, distinguishing between early-onset and late-onset disease. While the panel demonstrated high accuracy in classifying late-onset CAD, its ability to predict early-onset CAD requires further validation. Larger, independent populations are needed to validate the predictive ability of the panel for early disease detection, confirm these findings, and improve generalizability. Overall design: Prospective single-centre study of patients hospitalised for elective coronary angiography. Participants were stratified into three groups according to age and angiographic findings: non-CAD controls, early-onset CAD, and late-onset CAD. Fasting EDTA blood was collected, plasma was separated by centrifugation and stored at -80°C until processing. Total RNA including small RNAs was extracted from plasma, and small RNA libraries were prepared.