Abstract 15324: OCT-Derived Coronary Plaque Morphology and Transcoronary Concentration Gradients of Vessel Wall-Associated microRNAs
Introduction: Micro-RNAs (miRs) were experimentally shown to contribute to atherosclerotic plaque formation and stability. In order to establish a potential role for miRs as biomarkers to identify the presence of vulnerable coronary plaques in patients with CAD, we correlated transcoronary concentration-gradients of vessel wall-associated miRs with coronary plaque characteristics assessed by optical coherence tomography (OCT).
Methods: Blood samples were simultaneously obtained from the aorta and the coronary sinus in 31 patients. Plasma concentrations of the vascular smooth muscle-related miR-145, the endothelial-enriched miR-126, and the endothelial-activation-related miR-92a were measured by PCR. Comprehensive evaluation of the epicardial artery vessel wall by OCT was performed to quantify the extent of intramural lipid deposits, calcification, thin-cap fibroatheroma, macrophage content and intimal lacerations along the entire vessel length of the LAD and LCX.
Results: There was a significant positive correlation for transcoronary concentration gradients of both, miR-145 (r=0.45, p<0.05) and miR-126 (r=0.45; p<0.05), with the extent of macrophage density as well as with the extent of thin-cap-fibroatheroma (r=0.5; p<0.02 for miR-145 and r=0.5, p<0.02 for miR-126). In contrast, miR-92a concentrations in the coronary effluent were unrelated to atherosclerotic plaque characteristics. An increased vulnerable plaque load was associated with the release of the atheroprotective miRs miR-145 (see figure) and miR-126 (p<0.02) into the coronary circulation.
Conclusions: The present study is the first to document an association between vulnerable plaque load in epicardial arteries and the release of atheroprotective miRs from the vessel wall into the coronary circulation. miR-145 and miR-126 may thus be useful circulating biomarkers to identify patients at risk for subsequent plaque rupture.
- © 2012 by American Heart Association, Inc.