Comparsion of influence of enoxaparin with unfractioned heparin on acute myocardial infarction with ST-segment elevation

Background: Most patients with acute myocardial infarction with ST-segment elevation (STEMI) are still treated with pharmacological reperfusion which is not always successful. The aim of this study was to determine whether enoxaparin was associated with superior efficacy and safety compared with unfractionated heparin (UFH) in the STEMI setting. Methods: In this clinical trial, 150 patients less than 75 years old (104 men and 46 women) with STEMI who were scheduled to undergo streptokinase (1.5 milion unit per hour) randomly assigned to receive enoxaparin (40 mg intravenous bolus then 1 mg/kg subcutaneously BID) (group 1) or weight adjusted UFH from 24 to 48 hours after streptokinase (group 2). All patients underwent predischarge coronary angiography. Results: A number of 75 patients in group 1 (mean age 58.9 ±9.4) and 75 pateints in 2 (mean age 56.3±9.0) were studied. Two groups were well matched with respect to main risk factors and also other concomitant medications. Time from onset of symptom to start fibrinolysis and myocardial regions infarction were similar in both groups (p=0.13). Left ventricular ejection fraction were 45.2 ± 5.6 % in group 1 and 40.3 ± 7.3 % in group 2 (p=0.056). Major bleeding just was in 2 cases of group 1. Minor bleeding was in 10 cases of group 1 and 5 of group 2 (p>0.05). Conclusion: Our data showed a benefit of Enoxaparin compared with UFH in patients receiving fibrinolysis for STEMI with a mild trend toward an excess of bleeding. However, further well designed studies to assess these results with following patients for a longer period of time and also comparing therapeutic effects are needed