The Posthospital Phase of Myocardial Infarction

A prospective follow-up study was carried out on 100 patients recovering from acute myocardial infarction in order to develop a method for identifying those patients who are at high risk of late cardiac death. Variables, which were recorded just prior to the patient's hospital discharge after the acute attack, included six rhythm parameters from a six-hour tape ECG recording, three indices of severity of the acute coronary event, and seven nonspecific variables. Seventy-nine of the 100 patients survived a two-year follow-up, and 17 of 21 patients who died succumbed from cardiac-related problems. A stepwise discriminant analysis program was used to derive a formula which would predict the likelihood of surviving two years after a myocardial infarction. The population was divided into two groups on the basis of the presence (Group A, N = 67) or absence (Group B, N = 29) of ventricular premature beats on the initial ECG tape recording. In Group A, 91% of both the survivors and nonsurvivors were correctly identified by a discriminant combination of three arrhythmia parameters and age. In Group B, 75% of the survivors and 100% of the nonsurvivors were properly classified simply from age and one index of severity.