In patients with myocardial infarction with ST-segment elevation (STEMI), in which the infarcted artery is usually occluded and there is ongoing transmural ischemia, it is well established that the earlier primary percutaneous coronary intervention (PCI) can be performed, the lower the mortality. By contrast, in patients with acute coronary syndromes without ST-segment elevation (NSTEMI) including unstable angina and myocardial infarction, the culprit artery is often patent, there is usually no ongoing transmural ischemia, and the patient often has a good response to initial medical treatment. The optimal timing of such intervention has been uncertain.
New England Journal of Medicine - Vol. 360, No. 21, May 21, 2009