Subendocardial and transmural myocardial infarction: A five year survival study

Abstract

Two hundred seventy-six patients (median age 66 years) were discharged from the hospital following an acute myocardial infarction. Based on their electrocardiograms, they were divided into the following three groups: group 1, 127 patients with transmural infarction, i.e., with Q-wave development; group 2, 98 patients with subendocardial infarction, i.e., with S-T segment changes but without Q-wave development; and group 3, 51 patients with nondiagnostic electrocardiograms but with typical symptoms and enzymatic changes. The five year survival rates were not statistically significantly different (59 per cent, group 1; 51 per cent, group 2; and 41 per cent, group 3). Within the three groups, we found a statistically significant lower survival for (1) patients who were above 65 years of age, (2) patients who had a preadmission history of cardiovascular disease, (3) patients who had heart failure and arrhythmias during treatment in the hospital; and (4) patients who needed medical treatment on discharge. Thirteen per cent of the patients in the latter two catagories died suddenly within the first year. Thirty-three per cent of the patients with all these factors survived five years compared to 83 per cent of the patients with none of these factors. The electrocardiographic changes suggesting transmural or subendocardial infarction were not associated with differences in the long-time prognosis.