OBJECTIVEVery early-onset coronary artery disease (CAD) is a great challenge in cardiovascular medicine throughout the world, especially regarding its early diagnosis. This study explored whether circulating microRNAs (miRNAs) could be used as potential biomarkers for patients with very early-onset CAD.

METHODSWe performed an initial screening of miRNA expression using RNA isolated from 20 patients with angiographically documented very early-onset CAD and 20 age- and sex-matched normal controls. For further confirmation, we prospectively examined the miRNAs selected from 40 patients with very early-onset CAD and 40 angiography-normal controls.

RESULTSA total of 22 overexpressed miRNAs and 22 underexpressed miRNAs were detected in the initial screening. RT-qPCR analysis of the miRNAs obtained from the initial screening revealed that four miRNAs including miR-196-5p, miR-3163-3p, miR-145-3p, and miR-190a-5p exhibited significantly decreased expression in patients compared with that in controls (P<0.05). The areas under the receiver operating characteristic curve for these miRNAs were 0.824 (95% CI, 0.731-0.917; P<0.001), 0.758 (95% CI, 0.651-0.864; P<0.001), 0.753 (95% CI, 0.643-0.863; P<0.001), and 0.782 (95% CI, 0.680-0.884; P<0.001), respectively, in the validation set.

CONCLUSIONTo our knowledge, this is an advanced study to report about four serum miRNAs (miR-196-5p, miR-3163-3p, miR-145-3p, and miR-190a-5p) that could be used as novel biomarkers for the diagnosis of very early-onset CAD.