Infarct size after ST-segment elevation myocardial infarction (STEMI) is associated with long-term clinical outcomes. However, there is insufficient information correlating creatine kinase-MB (CK-MB) or troponin levels to infarct size and infarct location in first-time occurrence of STEMI. We, therefore, assessed the utility of CK-MB measurements after primary percutaneous coronary intervention of a first anterior STEMI using bivalirudin anticoagulation in patients who were randomized to intralesion abciximab versus no abciximab and to manual thrombus aspiration versus no aspiration.