Background:It has been reported that octogenarians (patients ���80 years old) with coronary artery disease constitute a particular risk group. However, there are a few reports about octogenarian acute myocardial infarction (AMI) patients in drug eluting stent (DES) era. The aim of this study was to identify clinical outcomes in octogenarian AMI patients compared with younger patients (non-octogenarian AMI patients). Methods:We retrospectively analyzed a total of9877 patients who were enrolled in Korea Acute Myocardial Infarction Registry (KAMIR) during the period from January 2006 to December 2008. They were divided to two groups, octogenarians (n=1494, 84짹4 years old), non-octogenarians (n=8383, 63짹11 years old). We compared in-hospital cardiac death, 1-year major adverse cardiac event (MACE) including cardiac death, recurrent myocardial infarction, target vessel revascularization (TVR), target lesion revascularization (TLR), and coronary artery bypass grafting (CABG) between two groups. Results:The prevalence of hypertension was significant higher, whereas that of hyperlipidemia, current smoking, and family history of coronary artery disease was significantly lower in octogenarians than in non-octogenarians.Patients status were also significantly severe in octogenarians, Killip classification class��� or ��� (17.0% vs.10.2%, p<0.0001), multi-vessel disease (65.8% vs.53.7%, p<0.0001).Rates of in-hospital cardiac death (13.0% vs. 3.7%, p<0.0001), 1-year cardiac death (19.4% vs. 5.8%, p<0.0001) were significantly higher in octogenarians. However, there was no significant difference in the rate of 1-year recurrent myocardial infarction (1.3% vs. 0.9%, p=0.290), TLR (2.4% vs. 3.1%, p=0.250), TVR (3.6% vs. 4.3%, p=0.334), CABG(0.9% vs.0.9%, p=0.948) between two groups. Conclusions:Percutaneous coronary intervention with DES would be an effective therapy even in octogenarian AMI patients compared with non-octogenarians.There was no difference in TLR/TVR rates between two groups with KAMIR subgroup analysis.