A DIFFERENCE BETWEEN FRONT-LOADED STREPTOKINASE AND STANDARD-DOSE RECOMBINANT TISSUE-TYPE PLASMINOGEN-ACTIVATOR IN PRESERVING LEFT-VENTRICULAR FUNCTION AFTER ACUTE MYOCARDIAL INFRACTION (THE CENTRAL ILLINOIS THROMBOLYTIC THERAPY STUDY)

A blinded, randomized trial compared the effects of front-loaded strep tokinase with those of the conventional dose of intravenous recombinan t tissue-type plasminogen activator (rt-PA) on left ventricular (LV) f unction after acute myocardial infarction (AMI). Thrombolytic therapy was administered in the emergency departments of 30 community hospital s in central Illinois, and subsequent studies were performed at 1 tert iary referral center. Patients aged less-than-or-equal-to 75 years wit h a first AMI who could be treated within 4 hours of the onset of ches t pain were randomly assigned to receive either streptokinase (375,000 IU bolus, followed by 1,125,000 IU over 1 hour) or rt-PA (10 mg bolus , followed by 50 mg in the first hour, and 20 mg/hour for the next 2 h ours). All patients were treated with aspirin (325 mg) and intravenous heparin. Patients were transferred for angiography within 24 hours. D uring the 30-month study, 253 patients were treated with intravenous t hrombolytic therapy 2.4 +/- 1.0 hour after the onset of AMI. In patien ts with anterior wall AMI (n = 90), global LV ejection fraction measur ed by angiography within 24 hours was 45 +/- 12% with rt-PA, and 39 +/ - 13% with streptokinase (p < 0.03). Convalescent radionuclide angiogr aphy documented a persistent beneficial effect of rt-PA on LV regional wall contractility, but not global ejection fraction. There were no d ifferences between rt-PA and streptokinase in preserving global or reg ional LV function in patients with inferior wall AMI.