Background: Effective myocardial reperfusion after primary PCI for AMI in lesions with a large thrombus is limited by distal embolization and slow/no reflow phenomenon. We evaluated the safety, feasibility, and efficacy of a thrombus reduction technique in using the EAC for thrombosuction before primary PCI in AMI. Method: We analyzed 61 patients with AMI who underwent primary PTCA and had a large thrombi burden in angiograpy using EAC(group I ; n=31, 25 males, mean ages 54.5짹11.6 years) or without EAC using(group II ; n=31, 20 males, mean ages 65.5짹12.2 years). After primary PCI, angiographic findings and clinical outcomes at 1 month and 6 months were recorded. Results: Baseline characteristics in both group were similar and angiographic success rate were 100%(31/31) and 87.1%(27/31), respectively(p=0.113). Although there were no different between two groups in incidences of distal embolization(p=0.612), slow/no reflow phenomenon were more commonly observed in group II(22.6%, 7/31) compared to group I(0/31)(p=0.001). The incidence of MACE during hospitalization(0% vs 7.7%, p=0.237) and follow-up duration(6.9% vs 0%, p=0.500) (7.4짹4.9 months) was not different between two groups. In 31 patients who were performed thrombosuction successfully, gross thrombi were obtained from 25 patients (80.6%) and, in 19 patients(61.3%), TIMI flow was improved by just doing thrombosuction without anymore intervention. Conclusion: Thrombosuction using EAC provide simple, rapid and potentially effective method for removal of thrombi burden and restoration of coronary flow before PCI in AMI.