Reduction of reinfarction and angina with use of low-molecular-weight heparin therapy after streptokinase (and heparin) in acute myocardial infarction.

This study examined whether extending the anticoagulation effect of heparin by low-molecular-weight heparin (clexane) can prevent recurrent myocardial infarction (AMI) treated by streptokinase. On the fifth day after AMI and after heparin therapy cessation, 103 patients were randomly assigned to either treatment with low-molecular-weight heparin (40 mg subcutaneously per day for 25 days, n=43) or control (no treatment, n=60). All patients were followed carefully for 6 months after the infarction date. A total of 32 patients (31%) sustained a cardiac event during the 6-month observation period. There were 12 patients (20%) with reinfarction in the control group versus 2 patients (4.6%) in the low-molecular-weight heparin group during the first 30 days of the study (p=0.02). One additional patient sustained reinfarction at 3 months of followup in the control group, which yielded a total of 13 patients (21.6%) sustaining reinfarction in the control group versus 2 patients (4.6%) in the low-molecular-weight heparin group during 6 months of followup (p=0.01). Angina pectoris after AMI was diagnosed in 13 control patients (21.6%) versus 4 low-molecular-weight heparin-treated patients (9.3%) (p=0.078) during the study period. No major bleeding events were reported in either low-molecular-weight heparin-treated or control patients. Among patients with recently diagnosed AMI treated by streptokinase, extending the anticoagulant effect of heparin for 25 days may prevent recurrent coronary events for at least one month.