Plasma Free Fatty Acids and the Incidence of Arrhythmias in Acute Myocardial Infarction during Treatment with Small Doses of Subcutaneous Heparin or Warfarin

In a prospective trial, 99 patients with a history of AMI of less than 12 hours were allocated at random to treatment with subcutaneous heparin, 5000 IU twice daily, (51 patients) or warfarin (48 patients). In a subsample of 21 patients, 11 in the warfarin group and 10 in the heparin group, fasting FFA analyses were performed before and 2 hours after administration of anticoagulants on days 1 and 2. No measurable increase in FFA concentrations was demonstrated in the heparin‐treated patients, in spite of a significant influence on the thrombin clotting time. The frequency of ventricular arrhythmias as detected by continuous tape recordings was equal in the two groups. It is concluded that subcutaneous heparin, 5000 IU every 12 hours, can be administered to patients with AMI without increasing the risk of arrhythmias as compared with warfarin. AMI= acute myocardial infarction,