Plasma free-fatty-acids and small doses of subcutaneous heparin in acute myocardial infarction

Abstract 21 patients with a verified acute myocardial infarction of less than 12 hours history were examined with fasting free-fatty-acids and coagulation assays (fibrinogen, thrombin clotting time and ethanol gelation test) the first 2 mornings in the coronary care unit. 10 patients received heparin 5000 IU subcutaneously every 12 hours, whereas 11 patients, selected by random allocation, received warfarin. Blood sampling was performed before and 2 hours after the administration of anticoagulants. An additional sampling for coagulation assays was performed on day 4. No differences in FFA values between the two groups were found. The absolute FFA values were in the upper normal range as a mean. Thus, no heparin-induced increase was demonstrated. The thrombin clotting time was within normal limits in the warfarin group, whereas significant prolongations were encountered in the heparin group, most pronounced on day 1. Increasing fibrinogen values were found in both groups from day 1 to 4, significantly more pronounced in the heparin group. At the same time increasing frequency of positive ethanol gelation tests were encountered, up to 60% on day 4 in both groups. It is concluded that subcutaneously administered heparin in small doses did not induce increased levels of FFA in patients with AMI, although significant influence on a sensitive coagulation test was demonstrated.