Low-dose heparin in the prevention of thrombotic complications following acute myocardial infarction.

103 patients with acute myocardial infarction (AMI), disqualified for thrombolytic treatment, were randomized into two groups. Group I received 5000 IU of heparin (subcutaneously, twice daily) for 14 to 21 days. Group II was without anticoagulant prophylaxis. Patients were evaluated for deep vein thrombosis (DVT) using radiofibrinogen uptake test and for the presence of intracardiac mural thrombus (ICT) by two-dimensional echocardiography (50 patients). The incidence of DVT was 4% in group I and 19% in group II. ICT was diagnosed in three patients (13%) of group I and in 10 patients (45%) of group II. Five patients under heparin prophylaxis and 6 non-anticoagulant patients died in the hospital of cardiac causes. There were no bleeding complications. Low-dose heparin seems to be an effective prophylaxis of thrombotic complications in patients with AMI.