Prophylactic Anticoagulant Therapy in the Prevention of Calf-Vein Thrombosis after Myocardial Infarction

Abstract In a controlled study of 92 consecutive patients with acute myocardial infarction prophylactic administration of heparin and warfarin reduced the rate of calf-vein thrombosis, detected by the 125I fibrinogen technic, from 22 to 6.5 per cent. Clinically important pulmonary emboli did not occur in either anticoagulated or nonanticoagulated patients. All patients studied were given active physiotherapy from the time of admission and mobilized within seven days of the acute infarction. Anticoagulant treatment thus appears to reduce the frequency of calf-vein thrombosis, but when a policy of early mobilization is followed, anticoagulation may be reserved for patients with evidence of thrombosis of veins above the knee or patients who are confined to bed for more than a week. (N Engl J Med 288:815–817, 1973)