Unresolved issues after the available comparative trials of thrombolytic agents in acute myocardial infarction.

Although the results of GISSI-2/International Study and ISIS-3 have confirmed the safety of streptokinase, they do not contradict the view that early recanalization, inducible with a higher incidence with rt-PA, is a primary determinant of clinical outcome. A definitive answer to the question must come from large scale mortality studies of patients in whom the risk/benefit ratio of thrombolysis is not unacceptably high, in whom electrocardiographic criteria of infarction are unequivocal, and in whom treatment can be initiated early after the onset of symptoms with regimens that will induce not only early recanalization, but also sustained patency in infarct-related arteries.