Objective:To evaluate the effect of diabetes on outcome of sirolimus-eluting stent.Methods:From December 2002 to May 2005,262 diabetes and 262 non-diabetics treated with sirolimus-eluting stents were studied.The follow-up angiography was performed in 8-month.Major adverse cardiac events(MACE)defined as death,myocardial infarction,or target lesion revascularization and follow-up angiography were analyzed.Results:Successful rate of stent implantation was 100%.There was no death during the procedure,hospitalization,and follow-up period.Acute myocardial infarction occurred in 1 diabetic at 2 days after PCI,and in 2 non-diabetics at follow-up period.Angiographic follow up at 8 months showed that absolute late lumen loss was 0.06 vs 0.04mm(P>0.05),relative late lumen loss was 2.32% vs 1.63%,and TLR rate was 12.60% vs 9.92% in diabetic group and non-diabetic group respectively.Logistic regression analysis showed that reference vessel lumen and relative late lumen loss were significantly associated with restenosis.Conclusion:Cypher stent implantation in diabetes is safe and effective,while relative late lumen loss may be related to restenosis.In a word,diabetes with small vessel may be considered to be risk factor for restenosis after Cypher stents implantation.