Primary PTCA for acute myocardial infarction reduced the risk of death, reinfarction, and stroke at the time of hospital discharge or within 30 days compared with fibrinolysis. Since in-hospital mortality rose significantly with increasing hospital delay, door-to-balloon time should be minimized when choosing a primary PTCA. PTCA was also performed for the treatment of non-ST elevation acute coronary syndrome in order to relieve chest pain and to ameliorate myocardial ischemia. There were, however, considerable ischemic complications after successful balloon dilatation so that intensive medical treatments to stabilize both patients and unstable plaque were recommended before the PTCA procedure. We had to wait for the introduction of coronary stents and newer antithrombotic agents to resolve these problems.