Background: Studies correlating intravascular ultrasound (IVUS) and clinical findings have suggested that positive remodeling (PR) in culprit lesions is associated with acute coronary syndromes and events at post-intervention. Objectives: The aim of this study was to assess the impact of remodeling pattern on other pre- and post-procedural IVUS findings in 310 acute myocardial infarction (AMI) patients (125 ST segment elevation and 185 non-ST segment elevation MI). Methods: PR (n=113) was defined as remodeling index (lesion/reference external elastic membrane cross-sectional area [CSA]) >1.05, intermediate remodeling (IR) as between 0.95-1.05, and negative remodeling (NR) as >0.95 (IR/NR group, n=197). Results: The plaque rupture (60% vs. 42%, p=0.004), multiple plaque ruptures (22% vs. 14%, p=0.014), thrombus (42% vs. 28%, p=0.012), hypoechoic plaque (62% vs. 41%, p<0.001), lipid-pool like image (40% vs. 26%, p=0.011), and scattered calcification (62% vs. 41%, p<0.001) were more common in PR group compared with IR/NR group. IVUS lesion length was longer (26짹16 mm vs. 22짹12 mm, p=0.026), lesion site plaque burden was greater (82짹36% vs. 76짹30%, p=0.014), and arc of calcium was smaller (97짹106쨘 vs. 150짹106쨘, p<0.001) in PR group compared with IR/NR group. Plaque cavity was significantly larger (2.8짹1.8 mm2 vs. 2.2짹1.4 mm2, p=0.016) and ruptured plaque length was significantly longer (3.2짹1.7 mm vs. 2.4짹1.2 mm, p=0.011) in PR group compared with IR/NR group. Post-stenting plaque prolapse was observed more frequently (36% vs. 22%, p=0.008), and cardiac enzyme was elevated more significantly after stenting in PR group compared with IR/NR group [CK-MB; +15.3짹22.1 U/l vs. +5.6짹11.1 U/l, p=0.022, and cTnI; +10.4짹15.6 ng/ml vs. +5.5짹9.4 ng/ml, p=0.008, respectively]. Conclusions: AMI patients with PR have more plaque vulnerability and higher frequency of plaque prolapse accompanied with post-procedural cardiac enzyme elevation compared with AMI patients with IR/NR