Though women develop heart disease later than men, they fare worse than men once they have it, and experts don't know why.
Dr. Richard Becker of the University of Massachusetts Medica1 Center in Worcester says women are more likely to die from a first attack and are also more likely to suffer another attack, reports a recent issue of American Health.In a study of 3,339 heart-attack victims, Becker found that 21 percent of the women either died or had a repeat heart attack within a year of their first. This compared with only 13 percent of the men.
Yet the severity of coronary artery disease among women was no greater than among men.
"The women on average were seven years older than the men - not enough of a difference to account for the women's higher heart attack rate," says Becker.
Before middle age, women are less prone to heart disease than men are - perhaps, researchers speculate, because the female hormone estrogen protects them. But after age 50 women quickly catch up.
One in nine American women aged 43 to 64 - and one in three over 65 - show some evidence of coronary artery disease. Nearly half of all American women die from heart or blood-vessel disease, making it the leading killer of women. Breast cancer, by comparison, kills one of every 30 American women.
For unknown reasons, coronary artery bypass surgery poses a greater risk for women. They're about twice as likely as men to die from it.
Cardiac surgeon Thierry Folliguet of Downstate Medical Center in Brooklyn, N.Y., studied 1,300 men and women who had undergone bypass surgery. He found about 12 percent of the women died within two months of the operation compared with 7 percent of the men.
But when he analyzed measures of heart-disease severity (including chest pain and number of diseased vessels) he found that the women's hearts were only slightly more diseased than the men's - not enough to explain the drastic differences in death rates.
He says his study should dispel the notion that doctors wait too long to treat women who have heart disease.
"It seems that gender makes a difference," says Becker. "But we need to explore the specific differences that may affect outcome following a heart attack."