EARLY USE OF ANTICOAGULANTS IN TREATMENT OF MYOCARDIAL INFARCTION

• Series of patients with myocardial infarction treated with anticoagulants have generally shown a decrease in death rate of one-third to one-half that seen in series of such patients on other types of treatment. The incidence of thromboembolic complications has been more strikingly reduced. Contraindications and caution must be observed with anticoagulant therapy is used, and laboratory facilities must be adequate to measure its effect on the blood. For rapid action, 1,200 to 1,500 mg. of ethyl biscoumacetate and 200 to 300 mg. of bishydroxycoumarin are given at the same time by mouth; thereafter the bishydroxycoumarin is given daily in doses, generally of between 25 and 50 mg., that will maintain the prothrombin time between 22 and 35 seconds as determined by the Quick one-stage method. In some patients it is desirable to give heparin, 75 mg. subcutaneously at 12-hour intervals for two or three doses. The anticoagulant effect of the coumarin and indanedione compounds can be terminated promptly if necessary by the use of phytonadione (vitamin K₁). It is frequently difficult to classify attacks of myocardial infarction as severe or mild during the early days of the attack. The decision as to which patients should receive any form of therapy must rest on the judgment of the physician.