Myocardial infarction prognostic scoring system. A myocardial infarction prognostic scoring system for patients treated in a coronary care unit is described. The prognostic significance of 22 variables, all which were available on admission, were analyzed. A prognostic index was then constructed by a modified stepwise logistic regressional analysis technique. The variables that were used in the scoring system were Killip hemodynamic class, infarct location, and the maximal ST segment elevation in a single lead. The scoring system was validated in an independent group of patients, including a group of patients treated with intravenous streptokinase. The scoring system may prove to be useful for individual patient prognostication and management strategies, and for the quantification of infarct severity for use in clinical studies. 