The influence of preinfarction angina pectoris (AP) on long-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) remains controversial. In 5,429 patients with acute myocardial infarction (AMI) enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto AMI Registry, the present study population consisted of 3,476 patients with STEMI who underwent primary PCI within 24 hours of symptom onset and in whom the data on preinfarction AP were available.