Objective To explore the effects of preoperative loading dose of rosuvastatin administered before percutaneous coronary intervention (PCI) operation on early cardiac function and cardiac troponin I (cTn I) and Cystatin C (CysC) levels in patients with acute coronary syndrome (ACS).Methods A total of 192 patients with ACS treated in our hospital were selected and randomly divided into an observation group and a control group (n=96,respectively).2 h before PCI operation,the observation group was administered with 40 mg loading dose of rosuvastatin,and after PCI operation 5 mg,once per night;the control group was only administered with 5 mg of rosuvastatin after the operation,once per night.The cardiac function and cTn I and CysC levels in patients before PCI and 2 d after the operation,and the incidence of major adverse of cardiovascular events (MACE) during hospitalization between the two groups were compared.Results Before the operation,there was no significant difference in LVEDD and LVEF between the two groups (P > 0.05);after the operation,LVEF in both groups increased significantly while LVEDD decreased significantly(P < 0.05),and the variation range of LVEF and LVEDD in the observation group was significantly higher than that in the control group(P < 0.05).There was no statistical difference in the preoperative cTnI values between the two grotps(P > 0.05),but the postoperative cTnI and CysC values between the two groups increased significantly (P < 0.05) and the increased range in the observation group was lower than that in the control group (P < 0.05).There was no significant change in the postoperative CysC value in the observation group (P > 0.05),while the postoperative CysC value in the control group was significantly higher than the preoperative one (P < 0.05).The incidence of MACE in the observation group (8.33%) was significantly lower than that in the control group (22.92%)(P < 0.05).Conclusion The loading dose of rosuvastatin before PCI operation can effectively improve the postoperative cardiac function of patients with ACS,protect the myocardial cells,reduce MACE during hospitalization,and is worthy of clinical use.