Therapeutic level in long term anticoagulant therapy after myocardial infarction: Its relation to recurrent infarction and sudden death

An examination was made of the PP (prothrombin-proconvertin) level during the total period of treatment and in connection with episodes of recurrent infarction and sudden death in patients on long term treatment with dicoumarol after myocardial infarction. The treatment was not significantly less satisfactory in 29 patients who had episodes of recurrent infarction than in the remaining 90 without such episodes. Further, episodes of recurrent infarction and sudden death occurred with PP values that were statistically in good agreement with the PP level during the total period of treatment. Thus, rises in the PP value above the therapeutic range were not responsible for these episodes. It is emphasized that the “prothrombin” values in connection with thromboembolic episodes are of interest only if we also know the therapeutic level during the total period of treatment. It is also pointed out that the incidence of recent thrombosis in the coronary arteries is much greater in cases of acute myocardial infarction than in cases of sudden death. Recurrent infarction is therefore a better parameter than mortality from cardio-vascular causes for the evaluation of the antithrombic effect of anticoagulants in coronary diesease.