Thrombolysis in acute myocardial infarction: need for a change in strategy and future directions

The results of several major trials of i.v. thrombolysis in patients with acute myocardial infarction have demonstrated the efficacy of the treatment in reducing mortality. Streptokinase and rt-PA have been shown to be effective (APSAC = anisoylated plasminogen streptokinase activator complex; GISSI = Gruppo Italiano per lo Studio della Streptochinasi nell' Infarto miocardico, ASSET = Anglo Scandinavian study of early thrombolysis, rt-PA). This treatment is associated with the potential for cerebral and major bleeding, especially in elderly patients. The benefit of this treatment in patients with cardiogenic shock or hypotension (ISIS-2) is discussed. There is no convincing evidence that patients with ST-segment depression or those with an equivocal electrocardiogram had been benefited from i.v. thrombolysis. Further studies with i.v. thrombolysis and/or other strategies need to be explored. Overall the use of i.v. thrombolytic agents in combination with PTCA in patients with acute myocardial infarction have resulted in improvement in ventricular function and survival in patients eligible for this therapy. However, new techniques and therapeutic approaches to prevent reocclusion, to prevent reperfusion injury, to prevent restenosis after PTCA, to prevent atherosclerosis in the infarct and non-infarct related arteries, and to reduce the potential for ventricular arrhythmias and sudden death as well as the potential for mural thrombi and embolization after infarction are needed. The 1990's will see attempts to determine the optimum adjunctive therapy or "cocktail" of agents to be used with i.v. thrombolysis.