Objective To investigate the preventive effect of atorvastatin calcium tablets(ACT)combined with colchicine(COL)on in-stent restenosis(ISR)after percutaneous coronary intervention(PCI).Methods Clinical data of patients with acute coronary syndrome(ACS)after PCI at Jianyang People's Hospital from January 2020 to June 2023 were retrospectively analyzed.According to the postoperative treatment plans after PCI,they were divided into the ACT group(Aspirin enteric-coated tablets+Clopidogrel bisulfate tablets+ACT)and the combined group(Aspirin enteric-coated tablets+Clopidogrel bisulfate tablets+ACT+COL).The observation indicators include minimum lumen diameter(MLD)within the stent,ISR rate,blood lipid parameters(HDL,LDL,TG,and TC),and inflammatory markers(hs-CRP and IL-35).In addition,the incidence of major adverse cardiovascular events(MACEs)and drug-related adverse reactions were observed and recorded.Results A total of 479 patients were included in the study,with 249 cases in the ACT group and 230 cases in the combined group.The difference in MLD between the two groups in the immediate postoperative period was not statistically significant(P＞0.05),and at 12 months postoperatively,the MLD of patients in both groups decreased significantly(P＜0.05),and the MLD of the combined group was lower than that of the ACT group(P＜0.05).The ISR rate was significantly lower in the combined group than in the ACT group(P＜0.05).The differences in preoperative lipid parameters and inflammation indicators between the two groups were not statistically significant(P＞0.05).LDL,TG,TC,and hs-CRP decreased significantly at 12 months postoperatively compared with preoperative period,while HDL and IL-35 increased significantly compared with preoperative period(P＜0.05).At 12 months postoperatively,the differences in HDL,LDL,TC,and TG between the two groups were not statistically significant(P＞0.05);compared with the ACT group,the hs-CRP levels in the combined group decreased significantly,whereas the IL-35 levels were elevated(P＜0.05).With regard to MACEs,the rate of myocardial re-infarction and the incidence of any MACEs events in the combined group were lower than those in the ACT group(P＜0.05),and the rate of emergency coronary revascularization,stroke and cardiac mortality were not statistically different(P＞0.05).Regarding drug-related adverse reactions,the differences between the two groups in the incidence of gastrointestinal reactions,the incidence of bleeding,the incidence of hematopenia,transaminase elevation,muscle soreness,infection,and any related adverse events were not statistically significant(P＞0.05).Conclusion ACT combined with COL improve inflammation levels and reduce the incidence of ISR and MACEs,in ACS patients after PCI,but has a smaller impact on blood lipid parameters.and without adding additional drug-related adverse reactions.