The characteristics of the endothelium after DES following implantation of calcified lesions have always been of interest to us. Its inherent peculiarities make the new endothelium of calcified lesions different.~Firstly, the presence of calcification makes the neointima heal slowly. In addition DES has an anti-proliferative effect, which further diminishes the healing ability of the neointima of calcified lesions and impairs the barrier function of the endothelium. This may have a similar pathway to the formation of neointimal atherosclerosis or heterogeneous endothelium within the neointima.~Secondly, stents with calcified lesions can be accompanied by incomplete stent expansion, stent fracture and stent misalignment. These conditions may accelerate the occurrence of restenosis within the stent.~Thirdly, there are different types of calcified lesions. Different types of calcified lesions may heal and restenosis in different ways.~It is therefore understood that calcified lesion healing has a number of pathways that exist in contradiction. These are issues that need to be explored in depth.
Previous studies have suggested that restenosis (RS) after stenting is mainly due to smooth muscle cell proliferation and migration, but recent evidence suggests that in-stent restenosis（ISR） is associated with a number of factors. Coronary artery calcification is an independent predictor of ischaemia-mediated revascularisation 1 year after percutaneous coronary intervention (PCI) following RS.The characteristics of new neointima in patients with in-stent restenosis of calcified lesions are important issues to explore