Myocardial infarction before age 36 years in women: Predominance of apparent nonatherosclerotic events

To examine whether myocardial infarction (MI) in young women resulted from atherosclerosis, we studied 19 women aged 18 to 35 years who had documented MI at our institution from 1955 to 1979. They were compared to 20 similar men who were selected randomly. All 20 men had at least one major coronary risk factor; six of the women did not (p < 0.01). The risk factors were up to four times more common in men. Coronary anatomy, defined in 13 women and 13 men, demonstrated patent vessels or single stenotic disease in 10 (77%) women but in only one (8%) man, and multilesion disease in only three (23%) women but in 12 (92%) men (p < 0.005). All with patent coronaries were women. Thus atherosclerosis is more advanced and accounts for most myocardial infarcts in young men, but is less evident and accounts for only a minority of MI in young adult women, who have a greater preponderance of nonatherosclerotic related infarcts.