Abstract: Objective To investigate the incidence,clinical predictors and in-hospital outcome of contrast-induced nephropathy(CIN) in patients who underwent primary percutaneous coronary intervention(PCI) for acute myocardial infarction(AMI).Methods Serum creatinine(Scr) concentration was measured before and 48-72 hours after PCI in 186 patients with acute ST-segment elevation myocardial infarction.Clinical characteristics and adverse events were observed during hospitalization.CIN was defined as an increase in serum creatinine of >25% or ≥44.2 μmol·L-1(0.5 mg·dL-1)from baseline within 48-72 hours following the procedure.Results Among the 186 patients,34(18.3%) developed CIN.Patients with CIN were more likely to be older(P<0.05) and had higher incidences of pre-existing renal insufficiency,left ventricular ejection fraction(LVEF)<40%,heart failure(Killip’s class≥2)than those without CIN(P<0.01).All patients with cardiogenic shock developed CIN at admission.The percentage of patients who received pretreatment with statin in CIN group was lower than that in non-CIN group(P<0.05).Multivariate Logistic regression analysis revealed that renal insufficiency(baseline Cr clearance<60 mL·min-1),implantation of intra-aortic balloon pump(IABP),cardiogenic shock and statin pretreatment were correlated with CIN.CIN group had longer hospital stay and more adverse events than non-CIN group(P<0.05 or P<0.01).Conclusion CIN frequently complicates primary PCI and is associated with higher incidence of in-hospital adverse events in patients with AMI.Pre-existing renal dysfunction and hemodynamic instability are the independent risk factors for CIN.Statin pretreatment is a predictor of decresed risk of CIN.