Survival in acute myocardial infarction; factors observed in 318 patients.

Factors influencing survival in a group of 318 cases of acute myocardial infarction were analyzed. The mortality rate for the entire series was 41 per cent. Among the men it was 39.5 per cent; among women, 44.4 per cent. The mortality rate increased with the age of the patient. Twenty-six per cent of all deaths occurred within the first 24 hours, 44 per cent within 72 hours, and 71 per cent within the first week following hospital admission. Increased mortality rate was associated with previous history of congestive failure, myocardial infarction, hypertension or cardiomegaly. As to circumstances immediately preceding an infarction, the only ones that seemed to be related to a high mortality rate were hemorrhage and the postoperative state. Not only the presence but the degree of shock, congestive failure, cyanosis and dyspnea adversely influenced chances for survival. Duration, location, radiation and number of attacks of pain did not appear to be associated with extraordinary mortality rates. Anterior was slightly more common than posterior infarctions, and the mortality rate was much higher. Thromboembolic complications and certain disorders of rhythm and of conduction definitely worsen prognosis. Comparison of average mortality data as reported in different studies on acute myocardial infarction is improper and misleading because of the great differences between the kinds of patients included in various series reported upon. A standard method of grading the severity of acute myocardial infarction would help toward sounder comparisons.