How does a woman's risk for heart disease change with age?

After 55, the chance of having a heart attack begins to rise precipitously in women. Not coincidentally, by that time, most women have gone through menopause, and the protective effects of estrogen -- raising high-density lipoproteins (HDL) and lowering low-density lipoproteins (LDL) levels -- are disappearing. Postmenopausal women are two to three times as likely to develop heart disease as women the same age who are still menstruating. But the Women's Health Initiative found that replacing estrogen with hormone therapy won't prevent heart disease, and it may even increase the risk of blood clots, heart attacks, and strokes.