Currently, percutaneous coronary intervention is an important treatment for coronary heart disease. However, the in-stent restenosis rate is still approximately 10-30% after stenting. Nickel ions from the stent are considered to be associated with in-stent restenosis. Therefore, in the present study, we quantitatively evaluated in-stent restenosis after implanting the novel high-nitrogen low-nickel coronary stent (HNS) and studied the mechanism underlying the reduction in in-stent restenosis by using ELISA and Western blot. The in vivo results showed that the HNS could significantly reduce neointima formation and inflammation as compared to SUS316L stents (316L) at 180 days after implantation in porcine coronary arteries and that vascular endothelial growth factor-A expression in porcine coronary arteries after HNS implantation also decreased. The in vitro results showed that, in the case of the HNS, human umbilical vein endothelial cell (HUVEC) proliferation was lower and lesser IL-6 release was noted from HUVECs at one and three days after culture than in the 316L group. Furthermore, p-STAT3 expression in HUVECs on the HNS surface was downregulated after culture for seven days. Thus, we conclude that the HNS could be a promising alternative coronary stent for percutaneous coronary intervention.
Keywords: Stent; coronary restenosis; inflammatory cytokines; low nickel; neointima formation.