Double bolus of 0.75 MU streptokinase plus enoxaparin versus front-loaded alteplase plus unfractionated heparin in ST-segment elevation myocardial infarction

Objective: To compare the efficacy and safety of an accelerated streptokinase regimen (double bolus of 0.75 MU in 10 min) in combination with enoxaparin (SK0.75Enox regimen) with the one of the front loaded alteplase (t-PA 100 mg/90 min) plus heparin (the t-PAHep regimen) in patients (pts.) with ST-segment elevation acute myocardial infarction (STAMI). Methods: One hundred seventy three pts. (age 18-74) treated within the first 6 hrs. after the onset of STAMI with the above two mentioned thrombolytic regimens were included. 1. The group SK0.75Enox (102 pts.) received an i.v. bolus of 40 mg Enox followed by 0.75 MU SK in 10 min. A second bolus of 0.75 MU SK would be administrated only if no bed-side signs of coronary reperfusion (CR) were detected within the next 50 min. After thrombolysis Enox was administered 1 mg/kg bodyweight every 12 hrs. for 5-7 days. 2. The group t-PAHep (71 pts.) received 15 mg of t-PA in bolus followed by 50 mg in 30 min and 35 mg within the next 60 min; t-PA was followed by heparin 1000 u/hour for the next 48-72 hours. All the patients received aspirin. Three noninvasive CR criteria were used: 1. Rapid cesation of the chest pain. 2. Rapid decrease of the ST segment elevation by more than 50% from the initial value. 3. Rapid increase of the CK and CK-MB with a peak within the first 12 hrs. Results: Two patients (2.85%) from the t-PAHep group had non-fatal stroke (one haemorrhagic, one ischemic). No other major haemoragical events were registered in both groups. During the thrombolytic infusion hypotension appeared more frequently in the SK0.75Enox group (31.4%) than in the t-PAHep one (8.5%) (p>0.0001) but without any consequence regarding the patients' outcome. The ratio of CR was 78.4% in the SK0.75Enox group and 70.4% in the t-PAHep one (p = 0.308). In-hospital reocclusion appeared in 4 pts. from the t-PAHep group (5.7%) but in none in the SK0.75Enox one. Six pts. (5.9%) from the SK0.75Enox group and 5 pts. from the t-PA one (7.04%) died within the first 30 days after the onset of STAMI (p = 0.993). Conclusions: The combination SK0.75Enox is at least as safe and efficacious as the t-PAHep one.