Data on more than one million patients was analyzed for the largest study of its kind ever done.
Compared to men, they are more likely to die in the hospital afterward.
One expert calls it a double whammy; not only do they not expect heart attacks in younger women - they are harder to diagnose when they occur.
Researchers say the study should raise awareness and alarm about women and heart attacks.
Details are in this week's Journal of the American Medical Association.
Women's symptoms:
- jaw pain
- shortness of breath
- weakness and fatigue
- heavy sweating and nausea, signs easily mistaken by women and their doctors as indigestion, flu, even stress
