Peripheral artery disease (PAB) is a narrowing of the arteries, most often in the legs. The presence of PAB is an indicator of generalized atherosclerosis, which is the leading cause of death in patients with vascular disease. The direct cause of the disease is not yet known, but the leading theory is that of damage to the vascular wall followed by an inflammatory response. When artery stenosis is large enough, an endovascular intervention is performed to expand the artery, which is percutaneous transluminal angioplasty (PTA). The success of the PTA is mainly determined by the occurrence of restenosis, which is a renarrowing of arteries, as it affects about one third of patients in the first six months after the procedure. Mechanisms involved in PAB and restenosis are still quite unexplored and research is now directed at micro RNAs (miRNAs), which are involved in endovascular inflammatory processes.
miRNA are small non-coding molecules that regulate the expression of genes after transcription. Recent studies have shown that certain miRNAs are involved in atherosclerotic processes, namely in differentiation, growth, proliferation, and apoptosis of vascular cells. The purpose of our research was to determine whether those miRNAs involved in the processes of atherosclerosis and PAB are also related to the process of restenosis.
Changes in the expression of three miRNAs: miRNA-590-5p, miRNA-1202 and miRNA-21 were monitored with reverse transcription (RT) and real-time polymerase chain reaction (qPCR) in patients with PAB following PTA of the femoropopliteal artery. The study included 123 patients of which 50 were women and 73 were men, aged 32-88. Based on the results of the ultrasound examination, patients were divided into two groups, with and without restenosis. 72 (59%) subjects experienced restenosis in the first 12 months after PTA. The occurrence of restenosis was the same with regard to sex and age but it had developed earlier in women, where 6 months after PTA 51% of women suffered from restenosis in comparison to just 31% of men. This difference was absent after 12 months. The expression of the selected miRNAs in blood after angioplasty increased more in patients who experienced restenosis than those without restenosis. There was no significant difference in the expression of all three miRNAs between patients with restenosis and those without it 1 month after PTA but there was a difference between the restenosis and non-restenosis group at 6 months and 12 months after PTA.
All of the selected miRNAs could be a potential predictive indicator for restenosis and therefore changes in the expression of all miRNA after PTA were included in the logistic regression model. The best predictive indicator is the change in the expression of miRNA-1202, the more its expression after PTA is increased the greater the likelihood of restenosis.