Alteration of circulating miRNAs during myocardial infarction and association with lipid levels

Background Increasing mortality and morbidity of coronary artery disease (CAD) highlight the emerging need for novel noninvasive markers such as circulating microRNAs (miRNAs).Objective To evaluate the circulating levels of miR-126-3p, miR-210-3p, let-7g-5p, and miR-326, and their associations with known contributors to CAD, in CAD subgroups.Methods We divided the cohort into 4 groups: non-CAD controls (<= 30% stenosis; n = 55), and patients with stable angina pectoris (SAP; n = 48), unstable AP (UAP; n = 46), and myocardial infarction (MI; n = 36). The circulating levels of miR-126-3p, miR-210-3p, let-7g-5p, and miR-326 were determined using TaqMan Advanced miRNA Assays in serum specimens.Results Circulating miR-126-3p levels were lower in the MI and UAP groups, compared with the non-CAD group, whereas miR-210-3p circulating levels were lower in the MI group than others. The levels of circulating let-7g-5p were shown to be useful for distinguishing UAP from MI, and there were substantial differences in circulating let-7g-5p levels between the UAP and MI groups. Moreover, lipid levels and ratios were lower in individuals with high circulating miR-126-3p and miR-210-3p levels.Conclusions The study results suggest that circulating miR-126-3p, miR-210-3p, and let-7g-5p are differentiated between different clinical presentations of CAD and associated with lipid levels, which are important risk factors and determinants of CAD.