To the Editor: Although Modan et al. caution that their study of anticoagulant therapy in myocardial infarction (N Engl J Med 292:1359–1362, 1975) is a retrospective one, and subject to all the pitfalls of that type of study, it is easy to be persuaded by their data that such therapy does have a role in the treatment of patients with myocardial infarctions. Dr. Feinstein, in an editorial in the same issue, asks if all the cogent factors have been included. I believe that they have not. I was taught medicine for six years in Israel, including the institutions that Modan….