Hogue theorized that decreased levels of the female hormone estrogen may contribute. Estrogen is believed to help protect women from heart disease prior to menopause. Some research has shown estrogen also protects brain cells from injury. Once women go through menopause, their estrogen levels fall to almost nothing. Most women who have cardiac surgery undergo the operations 10 to 15 years after menopause.
Men have estrogen in their bodies, although less than pre-menopausal women.
Men make it by converting some of the male hormone, androgen, into estrogen and thus can maintain some level of estrogen throughout life. The findings appear in Circulation , a journal of the American Heart Association. It already was known that women who have heart surgery fare worse than men. Two years ago, the researchers found that among 3,000 heart surgery patients treated at Washington University, women had a higher risk for stroke. They then tried to learn whether this trend could be seen nationwide.