ABSTRACT
ST-elevation myocardial infarction (STEMI) is a major cause of cardiovascular morbidity and mortality. Fibrinolytic therapy is recommended in STEMI patients with (i) symptom onset within 12 hours, (ii) greater than 0.1 mV ST-segment elevation in at least two contiguous ECG leads or new left bundle branch block, and (iii) low bleeding risk (1). It restores infarct artery patency, reduces infarct size, preserves left ventricular function, and decreases mortality in patients with STEMI. Three seminal events ushered in the ‘‘fibrinolytic era.’’ First, DeWood and colleagues (2) performed acute coronary angiography in patients with STEMI and showed that 87% had thrombotic coronary artery occlusion within 4 hours of symptom onset, but only 54% did 12 to 24 hours after onset. Coronary thrombosis had previously been thought to be a postmortem finding. Second, Rentrop and coworkers (3) demonstrated that occluded infarct arteries could acutely be reperfused with an intracoronary streptokinase infusion. Third, Reimer et al. (4) demonstrated in a dog model that myocardial necrosis after coronary artery occlusion spread from the endocardial surface to the epicardial surface over a period of hours. Restoration of arterial patency before three hours preserved an epicardial rim of viable muscle, establishing the anatomical justification for reperfusion therapy to modify infarct size.
