Abstract: Objective To investigate the effect of stressinduced hyperglycemia（SHG）on myocardial perfusion and clinical prognosis in elderly patients with acute myocardial infarction（AMI）  who underwent primary percutaneous coronary intervention（PCI）. Methods A total of 459 elderly patients with firsttime occurrence of acute STelevation myocardial infarction（STEMI）  who underwent primary PCI within 12 hours were enrolled and followed up.All patients were divided into three groups according to serum glucose（SG）  on admission：normal group（SG＜7.0  mmol/L，n=148）；SG elevation group（7.0 mmol/L≤SG≤11.1 mmol/L，n=169） and （steady high blood glucose）SHG group（SG＞11.1 mmol/L，n=142）.Myocardial perfusion indexes，including ST segment resolution（STR），TIMI myocardial perfusion grade（TMPG），peak value of creatine kinase CKMB，left ventricular ejection（LVEF），and major adverse cardiac events（MACE） of patients in three groups  were measured and compared after emergency PCI.Results  The sa levels were increased，STelevation 2 h after PCI were well declined，the percentages of patients with TMPG 23 were decreased and peak values of CKMB were increased in three groups（all P＜0.05）.After 12 months’  followup，KaplanMeier survival analysis showed that patients of three groups had significantly different cumulative nonevents survival rates，89.2％（132/148）vs 85.8％（145/169），76.1％（108/142）(P＜0.05).Muhivariate Cox regression analysis showed that steady high sa were the independent predictor for the occurrence of MACE in patients undergoing PCI after adjusting for age and gender. Conclusion SHG in elderly patients with STEMI can decrease myocardial perfusion level after primary PCI，which will lead to high incidence of MACE.

Key words: myocardial infarction, percutaneous transluminal coronary angioplasty, myocardial reperfusion, hyperglycemia