Effect of very early intravenous streptokinase infusion in patients with evolving myocardial infarction.

The effect of very early infusion of 1.5 X 10(6) U of streptokinase intravenously was studied in 29 patients with nitroglycerin-resistant chest pain and ST-segment elevation. Infarct size was estimated from maximal LD1 isoenzyme levels, and the diagnosis confirmed by CK-MB determination. Thrombolytic therapy was started within 1 hour of pain onset in 11 patients (group A), between 1 and 2 hours in 10 (group B), and later than 2 hours in eight patients (group C). Marked differences appeared between the groups. Thus, three patients in group A and one patient in group B did not develop infarction, all had critical LAD stenoses. Three patients in group C died in shock without bleeding. Further, the average maximal LD1 values in the 22 patients who survived their infarction differed significantly between the groups, and were 12.6, 19.1 and 36.2 mu kat/l in groups A, B and C, respectively. In conclusion, very early intravenous streptokinase infusion probably reduces myocardial necrosis, and possible prevents infarction in some patients.