Abstract 17798: Plasma Cardiac miRNA Expression During ST Elevation Myocardial Infarction

Abstract

Introduction: MicroRNAs (miRs), short sequences of RNA that silence gene expression, have been proposed as biomarkers potentially capable of detecting myocardial infarction earlier and more accurately than troponin. Few studies have assessed expression patterns of cardiac-relevant miRs at the time of ST elevation myocardial infarction (STEMI). Hypothesis: Plasma levels of miRs known to regulate myocardial processes are altered in the plasma of patients early after STEMI onset. Aim: To establish a signature of miRs differentially expressed in plasma of patients with STEMI at the time of presentation. Methods: 10cc blood was obtained at the time of coronary angiography for patients presenting with STEMI(n=9), and plasma was recovered after centrifugation. Patients without coronary heart disease who had undergone coronary angiography served as referent normals(n=5). Following RNA extraction, RT-qPCR was performed to quantify levels of 84 cardiac miRs (Qiagen, Germany) with fold change calculated by the 2 - ΔΔCt method. Results: The mean age was similar between STEMI and referent normal control patients (59±9 vs 60±8), and the mean troponin was numerically higher in the STEMI group (15.4±21 vs 0.00±0; p=0.13). As shown in the table, the expression levels of 25 miRs were significantly increased, and 2 were decreased as compared with control patients (p<0.10). Seven miRs were not detected, and the remaining 47 detectable miRs were not different between the groups(p≥0.10). Cardiac-specific miR-499a-5p and miR-208b-3p demonstrated the greatest fold-change relative to referent normal patients. Conclusions: Cardiac-specific miRs, most notably miR-499a-5p and 208b-3p, as well as many other miRs are differentially expressed early after STEMI onset. Further work is needed to determine whether miRs can detect STEMI earlier or more accurately than troponin or provide incremental diagnostic value for patients presenting with acute coronary syndromes.