Association of Circulating microRNAs in Plasma with Coronary Collateral Circulation in Patients with Chronic Total Occlusion

Chronic total occlusion (CTO) occurs in 16–52% of patients with coronary artery disease (CAD) and is often accompanied by variable development of coronary collateral circulation (CCC). The aim of this work was to study the associations between circulating plasma microRNAs (miRNAs) and the development of CCC in patients with CTO. This exploratory study included 43 patients: a control group—patients without significant coronary artery stenosis (n = 20), and two CTO groups with good (n = 13) and poor (n = 10) CCC based on the Rentrop classification. The study was performed simultaneously on two types of plasma samples (K2EDTA and sodium citrate). Total RNA was isolated using the miRNeasy Serum/Plasma Advanced Kit. Libraries were prepared using the QIAseq miRNA UDI Library Kit and then sequenced on the NextSeq 550 using a 1 × 75 bp protocol. A total of 18 miRNAs were found to be differentially expressed (DE) in EDTA plasma and 13 in citrate plasma; only one miRNA in citrate plasma (hsa-miR-92a-3p) was differentially expressed between the good and poor CCC groups. However, given the limited sample size, the findings should be considered hypothesis-generating, and further studies are required for validation in larger, independent cohorts and to establish the roles of these miRNAs in CCC development.