Thrombolytic therapy in acute myocardial infarction

Myocardial infarction (MI) usually results from complete or near total obstruction of an epicardial coronary artery by a ruptured atherosclerotic plaque with adherent thrombus. The fundamental goal of reperfusion therapy for MI is to prevent tissue necrosis by restoring blood flow to ischemic myocardium. The progression from irreversible to reversible myocite injury is time dependent, and the amount of tissue salvage should relate to the rapidity of reperfusion (short time >>do to nidle<<). More rapid restoration of flow,through the infarct-related artery after the initiation of thrombolytic therapy may better preserve left ventricular function and improve survival among patients with MI. Ideally, reperfusion should minimize infarct size and the clinical sequel of myocardial injury without causing adverse systemic effects (stroke, gastrointestinal bleeding). The value of thrombolytic therapy for patients with AMI has been firmly established by the results in more than 100 000 patients in many trials: the first two large trials with mortality as the major endpoint such as GISSI and ISSI-2 and many smaller or also large trials which used infarcts size, left ventricular function or vessel patency as endpoints: TAMI, TIMI, ASSET, GUSTO, GISSI-2, ISIS-3. There are prevented approximately 30 deaths per 1 000 patients treated within first 6 hours of onset, and 20 deaths prevented per 1 000 patients treated within 7-12 hours of onset of AMI.