Backgrounds and Objectives: Although drug-eluting stents (DES) are more effective than bare-metal stents in preventing coronary restenosis, stent underexpansion was known to be an important predictor of early stent thrombosis and restenosis in the DES era. Recently, a large retrospective study demonstrated that post-dilatation after DES implantation reduced the restenosis rate. However, the population of the study did not include patients with acute myocardial infarction (AMI). The aim of present sub-study of EVER-ZOTA multicenter trial was to evaluate the impact of an adjunctive post-dilatation after DES implantation on the clinical outcomes in patients with AMI. Methods: We studied 474 (343 men, 65 짹 12 years old) patients who underwent DES implantation for AMI including 358 with postdilatation (253 male, 66 짹 12 years old) and 116 with un-postdilatation (90 male, 63 짹 12 years old). Rate of cumulative 12-month events, such as cardiac death, target-vessel related MI, revascularization, or stent thrombosis were compared between groups. Results: Compared with the postdilatation group, the un-postdilatation group had younger, less calcified lesion, and obtained postprocedural TIMI-3 flow. They had also significant benefit on composite events in 12 months (5.6% vs. 0.9%, p < 0.045)(Figure). However, Cox regression survival analysis showed the Killip Class ��� 3 (odd ratio 17.271, 95% CI 5.433-54.906, p<0.001) and age (odd ratio 1.061, 95% CI 1.005-1.119, p=0.031) to be independent predictors of 12-month composite events rather than postdilatation itself. Conclusion: Postdilatation after DES implantation in patients with AMI does not seem to have a benefit on the 12-month clinical outcomes. Clinical factors, such as age and Killip Class rather than postdilatation itself would be more predictive of 12-month clinical outcomes.