Myocardial infarction in young adults may differ from that in the elderly is terms of clinical characteristics and angiographic findings. The aim of this study was to evaluate the prevalence of various risk factors; also, coronary angiographic characteristics of acute myocardial infarction in patient under 40 years old were compared to that in patient over 40 years old.

We studied 239 patients with acute myocardial infarction who were admitted to Wonju Christian Hospital from 1990 to 1995 and evaluated the clinical and coronary angiographic characteristics.

The incidence of acute myocardial infarction in patients under 40 years old was 10.8% (26/239) and were predominently. In men, risk factor analysis revealed the followings ; hypertension was more frequent in elderly patients, and in contrast, smoking history was more frequent in younger patients. Other risk factors did not significantly differ between the two groups. Normal coronary artery was more frequent in the younger patients. The diameter stenosis of the infarct related artery was also less servere in the younger patients. In-hospital morbidity and mortality were not significantly different between the two groups.

Men and smokers were predominent in patients with acute myocardial infarction under 40 years old. The vessel involvement and the diameter stenosis of infarct related artery were less servere in patients with acute myocardial infarction under 40 years old than patients over 40 years old.