Pioglitazone is used in the treatment of diabetic patients. Thiazolidinediones increase insulin sensitivity and show favorable effect on blood glucose levels and lipid profiles. The effect of pioglitazone on atherosclerotic and inflammatory markers has not been compared in prospective manner after everolimus-eluting stent implantation by OCT. The purpose of this prospective, randomized, open-label trial is to compare the effect of pioglitazone on neointima volume and atherosclerosis progression in type 2 diabetic patients by using OCT. Moreover, changes in neointima characteristics could be analyzed along with the changes in miRNA-21, -126, -143, -145. Major adverse cardiovascular events such as non-fatal MI, death, stroke, and TLR could be compared.