Quantitative assessment of myocardial infarction prognosis to 1 and 6 mth--from clinical data

Abstract

Survival of 312 patients with acute myocardial infarction was studied from data collected during the first 48 h in the coronary care unit. Only patients with recent onset of symptoms (48 h), with a 48-h survival, and with evidence of myocardial infarction, were selected. Mortality rate at 1 mth was 15.3% and 24.6% at 6. The following factors were significant for poor survival: increasing age, female sex, diabetes, previous angina, low blood pressure on admission and at the 48th h low average value and the lowest observed value of blood pressure, clinical and radiological left ventricular failure, high level of LDH, increased urea and leukocytosis. Among ECG data, the presence of signs related to extent of infarction, anterior as compared to inferior location, antero-lateral as compared to anterior, QRS frontal axis deviation, absence of sinus rhythm, sinus tachycardia, tachyarrhythmias with wide QRS complex, right bundle branch block, 3rd-degree AV block with wide QRS complex, was associated with significantly worse survival than the absence of these signs. A multivariate analysis of the 42 most significant data, assuming linear regression, was used to establish a discriminant prognostic index. Using this index, survival was predicted correctly in 90.2% of patients at 1 mth and 85.7% at 6 mth. Thus prognosis can be established in nonclear-cut groups of patients with myocardial infarction (severe and benign forms being excluded by criteria) from simple clinical data.