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.