Thrombolysis in acute myocardial infarction: effect of intravenous followed by intracoronary streptokinase application on estimates of infarct size.

The effect of pretreatment with intravenous infusion of streptokinase (SK) (16,700 U/min for 90 minutes), started after diagnosis and followed by intracoronary application (2000 U/min) (protocol 1), was assessed retrospectively in 55 consecutive patients with acute transmural myocardial infarction (MI). Another 46 patients with acute MI treated previously by intracoronary thrombolysis served as control subjects (protocol 2). Reperfusion at first coronary injection was observed after pretreatment in 25 patients (45%), but in no control patient (p less than 0.001). Fifteen patients with successful pretreatment (group A), 20 patients with successful treatment according to protocol 2 (group B) and 9 patients with unsuccessful thrombolysis (group C) were restudied after 4 weeks. Data from patients with reinfarction, coronary bypass surgery or percutaneous transluminal coronary angioplasty before restudy were excluded. Thallium-201 scintigraphy was performed before and 24 hours after treatment, serum creatine kinase activity was measured every 8 hours for 3 days and regional ejection fraction (EF) of acute MI was determined before and 4 weeks after treatment. The scintigraphic, enzymatic and hemodynamic data before treatment indicated severe and comparable ischemia among the 3 groups. The thallium-201 perfusion defect decreased in group A (from 41 to 21%, p less than 0.01) and in group B (from 38 to 26%, p less than 0.01), but did not change in group C (from 37 to 31%, difference not significant). Peak serum creatine kinase levels normalized by the perfusion area of acute MI was 20, 33 and 58 U/liter unit in groups A, B and C. The mean values of groups A and C were significantly different (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)