Treatment with PCSK9 inhibitors influences microRNAs expression and changes of arterial wall properties

Background: MicroRNAs (miRNAs) are involved in the synthesis of proprotein convertase subtilisin–kexin type 9 (PCSK9), one of the regulators of low-density lipoprotein cholesterol (LDL-C) metabolism, and are directly involved in the atherosclerotic process. The aim of this study was to verify whether treatment with PCSK9 inhibitors (PCSK9i) and changes in the expression of miRNAs involved in PCSK9 metabolism are associated with arterial wall properties in stable post-myocardial infarction (MI) patients with insufficiently regulated LDL-C levels and significantly increased Lp(a) levels. Methods: Ninety-five patients after MI were enrolled and randomized to a placebo (N = 31) or PCSK9i group (N = 64). The treatment group received subcutaneous alirocumab 150 mg or evolocumab 140 mg, every 2 weeks. Blood for biochemical and epigenetic analysis was taken and ultrasound measurements of flow-mediated dilation of brachial artery (FMD), carotid intima–media thickness (c-IMT) and pulse wave velocity (PWV) were performed initially and after 6 months of treatment. The expression of the selected 5 miRNAs (miR-191-5p, miR-224-5p, miR-337-3p, miR-483-5p, and miR-552-3p) was quantified using quantitative polymerase chain reaction. Results: A decrease in c-IMT was associated with a decrease in the expression of miR-337-3p (ρ = 0.329