OBJECTIVES: To the estimate the health care utilization patterns and costs related to ST-elevation acute myocardial infarction(STEMI) and understand the pattern of anti-thrombolytic use after stenting with a Korean population based design. METHODS: We extracted the insurance claims records of STEMI patients defined as diagnosed with AMI and admitted by emergency room from Korea National Health Insurance claims database. We examined the health care service provided to stent naïve patients among STEMI patients defined as having no coronary-stents during one-year washout-period and having stents during two-year intake-period(January 1, 2006-December 31, 2007). Annual claims records were aggregated for each patient to produce patient-specific information on total utilization, costs and anti-thrombolytic use. We examined the pattern of anti-thrombolytic use according to types of the first stents(groupI as using drug-eluting stents[DES], groupII as using bare-metal stents[BMS]) and types of revascularization method(group A-DES, group B-BMS, group C-balloon, group D-CABG). RESULTS: There were 19,120 subjects identified as STEMI patients. Each STEMI patient had 8.7 outpatient visits, 1.1 admission per year. The total costs for treating STEMI in the nation was estimated as Korean-won(KRW)106,666million. The per-capita insurance-covered costs were KRW3,721,390. Those increased until the age of 74years and reduced after the age of 75years. The annual number of claims in tertiary hospital was slightly fewer than secondary hospitals(13,303 VS 13,730), but insurance-covered costs/claim in tertiary hospital were higher than those in secondary hospitals by KRW1,493,051. The duration of using Cilostazol from the first stenting to revascularization in group I was 79.12days, while GroupII was 73.44days. The use of Cilostazol was longer in groupIA(95.8days) or IC(89.18days) than groupIIA(62.15days) or groupIIC(61.33days). CONCLUSIONS: In Korea, the burden of illness for AMI is a significant issue. Cilostazol was used longer when DES were used at first stenting compared to BMS. Whether the longer usage of Cilostazol results in better outcome needs further research.