Myocardial infarction in young adults: angiographic characterization, risk factors and prognosis (Coronary Artery Surgery Study Registry).
OBJECTIVES: This study examined the angiographic characteristics, coronary risk factors and prognosis in young men and women with a history of myocardial infarction compared with that in older patients. BACKGROUND: There are few data regarding myocardial infarction in young adults. It is undetermined whether the development of myocardial infarction at a young age represents a form of coronary heart disease with an adverse prognosis. METHODS: Of the 8,839 patients with a history of myocardial infarction in the Coronary Artery Surgery Study (CASS), there were 294 men < or = 35 years old and 210 women < or = 45 years old. Coronary anatomy, baseline characteristics and prognosis were compared in younger and older patients. RESULTS: Young men and women more often had angiographically normal coronary arteries, nonobstructive disease < 70% stenosis and single-vessel disease than older patients (p < 0.0001). Current smoking was more frequent in young patients (p < 0.0001). Hypertension and diabetes were more frequent in both older men and women, whereas a positive family history of premature coronary disease was significantly more prevalent only in young men. The survival rate at 7 years was improved for young men compared with that in older men (84% vs. 75%, p = 0.0094) and for young women compared with that in older women (90% vs. 77%, p = 0.0004). When multivariate analysis was applied to the data, the survival advantage for young patients remained after adjustment. CONCLUSIONS: Young patients with a myocardial infarction have a favorable prognosis compared with that in older patients.