There are more than 600,000 acute myocardial infarctions (AMIs) in the United States each year, with direct medical costs exceeding $16 billion per year. Two treatment strategies are available for AMI today: medical therapy, including thrombolytic therapy, and primary angioplasty. Despite provocative preliminary data suggesting primary angioplasty results in lower mortality, morbidity and cost compared with thrombolytic therapy, most observers caution that more information is required before primary angioplasty replaces thrombolytic therapy for the treatment of AMI.