Backgrounds: Primary PCI in patients with ST-segment elevation myocardial infarction (STEMI) may cause thrombus dislodgment and impaired microcirculatory reperfusion. We elucidate whether thrombus removal, with a thrombus-aspirating device and glycoprotein IIb/IIIa inhibitor, during primary PCI may improve myocardial reperfusion and long term mortality compared with standard PCI Methods: Total 169 patients (male: female=125:44, mean age: 62짹12 yrs) who underwent primary PCI since 2005 year were enrolled. Achievement of more than 70% resolution of ST segment elevation (STR) at 90min ECG after procedure, post procedural TIMI 3 grade and myocardial blush 3 grade (MBG) were compared in the mechanical aspiration (Export, Medtronic, group 1, n=27), GP IIb/IIIa inhibitor (group 2, n=19), both (group 3, n=10) and conventional PCI group (group 4, n=113). Also, MACE rate at 7 day and 18 month after PCI were compared respectively. Mean duration of follow up was 21짹9 months. Results: Comparing groups 1,2,3 and 4, Difference of complete STR rate among the groups did not reach statistical significance. But, Achievement rate of TIMI 3 grade was significantly high in aspiration combined with GP IIb/IIIa inhibitor group. Also MBG-3 grade was more frequently found in aspiration group. Nevertheless, Mace rate at 7 day and 18 month were not different among the groups (Table 1).Conclusion: Mechanical aspiration and GP IIb/IIIa inhibitor leads to better myocardial perfusion and angiographic TIMI grade. But angiographic improvement did not affect MACE rate at short term or long term follow-up period during the primary PCI in patients with STEMI

Group	1.Asp	2.GP	3.Asp+GP	4.Conventional
TIMI 3 grade (%)	7 (43.8)	3(30.0)	9*(100)	25(18.8)	P=0.001
MBG-3 (%)	8*(80)	4(66.7)	3(42.8)	32(68.1)	P=0.023
Complete STR (%)	7(41.2)	6(60.0)	5(55.6)	71(56.8)	n-s
MACE (%) 7d	2(11.8)	0(0)	1(11.1)	10(7.5)	n-s
18 mon	2(11.8)	0(0)	1(11.1)	12(9.0)	n-s
Total	16	10	9	133