Anticoagulant Administration after Cardiac Infarction BrD

5-10% but was sometimes found when the level was 10-25%. Though relating to a different therapeutic problem their results may be relevant. The average daily dose of 72 mg. of phenindione in this trial was less than the mean daily dose of 108 mg. used in the M.R.C. long-term anticoagulant trial (Report to Medical Research Council, 1959, 1964). The moderate anticoagulant effect might explain the low rate of haemorrhage in this trial, which is lower than that in the Danish trial or in the American Heart Associationr trial (Wright et at., 1948 ; Hilden et al., 1961a). The occurrence of haemorrhage in the low-dosage group in this trial was also lower than in the control group in the American Heart Association trial, so that differences in reporting levels may also be suspected. Since this trial was designed to compare the results of allocation at an early stage of the investigation of the case, our series contained about 8% of patients in whom the, diagnosis was not later confirmed, but they were equally distributed between highand low-dosage groups. In some of these patients, and in others where complications such as haemorrhage or thromboembolism supervened, changes in treatment were made; 8% of the high-dosage group and 12% of the other group were thus affected. About 90% of the patients in each group were thus maintained on the same anticoagulant regimen throughout the 28 days of their stay in hospital. In this trial there was a low case fatality rate (18%) in the low-dosage group in comparison with the usual reported experience of 30% death rate in patients with myocardial infarction admitted to hospital. Possibly important was the exclusion from the trial of patients suffering, for example, from severe hypertension or giving a history of previous cerebrovascular accident. It should be noted that a small proportion of patients (see Table XIII) were admitted to the trial 48 hours or longer after the onset of the incident of infarction when the fatality rate is lower than during the first 24 to 48 hours. An important difference between this and earlier trials may lie in the major changes that have taken place in the treatment of acute myocardial infarction. Any reduction in the risk of thromboembolism attributable to earlier mobilization, for example, may well diminish the potential contribution of anticoagulant drugs to the prevention of such complications of myocardial infarction. It should be emphasized, therefore, that our conclusions relate specifically to the degree of anticoagulant effect produced in the patients selected on the criteria stipulated and in the context of the ancillary forms of treatment prevailing while this trial was in progress.