Background: A higher loading dose of clopidogrel (600mg) before a stent procedure produces favorable results; however, a strategy of pretreatment with clopidogrel in patients who have not already had their coronary anatomy defined is controversial. Method: To evaluate the role of high dose clopidogrel loading, we retrospectively reviewed the clinical spectra of patients having a triple pretreatment (aspirin 300 mg, clopidogrel 600 mg, atrovastatin 40 mg) according to our current ACS-ER strategy. Results: For the 6 months (Jan.-June 2006), 84 patients had visited our ER for ACS. A total of 83 patients (age 60짹13 years, male 58) who had the triple pretreatment were enrolled. Among them, 76 patients (92%) had a PCI, and finally, at least one coronary stent was used in 50 patients (60%): directly from the ER (41/64 patients) or via CCU (9/12 patients). Figure 1 summarized their clinical courses. There were no major bleeding complications in any medical courses. However, in all three cases (interval from clopidogrel to cath: 5, 5, and 10 min) of emergency CABG, bleeding control was cumbersome in the operation room and showed substantial chest tube output (first 24 hrs, total: 320, 2910; 250, 1290; 550, 2270 ml). One of them had another operation with hematoma evacuation. Conclusion: There were various clinical courses in patients with ACS in the ER. It might be reasonable that in hospitals where patients with ACS routinely undergo early PCI, clopidogrel not be started until it is clear that CABG will not be scheduled within the next several days.