Women's Health

New Way to Predict Women's Heart Risk

Feb. 16. 2010 -- New guidelines for predicting women's heart disease risk, updated in 2007 by the American Heart Association (AHA), work well, according to researchers who put the new strategy to the test.

The guidelines recommend a simplified approach to assessing a woman's heart disease risk, categorizing it as high risk, at-risk, or optimal risk.

The researchers evaluated how well the guidelines worked by testing them with participants in the Women's Health Initiative (WHI), which enrolled more than 160,000 women, ages 50 to 79. Next, they compared it to a commonly used approach for predicting cardiovascular disease risk from the long-running Framingham Heart Study.

''The advantage to the 2007 AHA guideline is that it's simple," says study researcher Judith Hsia, MD,  director of clinical research at AstraZeneca, who conducted the study while a professor of medicine at George Washington University in Washington, D.C.

"One drawback is, it's only for women," she says, although ''there is no reason it shouldn't work for men."

Hsia and colleagues categorized the women from the WHI study as high risk, at-risk, or optimal or low risk, depending on risk factors. (The WHI study evaluated the effect of hormone therapy, diet, calcium, and vitamin D on heart disease and cancers.) Here are the characteristics of each category:

• High-risk women have known cardiovascular disease, diabetes, or end-stage or chronic kidney disease.
• At-risk women have more than one major risk factor for heart disease (such as cigarette smoking, poor diet, inactivity, obesity, family history of early heart disease, high blood pressure or cholesterol, evidence of ''subclinical'' vascular disease, metabolic syndrome, or poor treadmill test results).

Optimal or low-risk women have a healthy lifestyle and no risk factors. A healthy lifestyle included exercising the equivalent of 30 minutes of brisk walking six days a week and eating less than 7% of total calories from saturated fat.

The Framingham Heart Risk Method

Hsia's team compared the new AHA approach to one commonly used approach from the Framingham Heart Study, a long-running study of heart disease launched in 1948, that uses seven characteristics to compute the predicted risk of heart problems over the next 10 years:

• Age
• Gender
• Total cholesterol
• HDL "good" cholesterol
• Systolic blood pressure (upper number)
• Need for blood pressure medication
• Cigarette smoking

For instance, a woman who is 50 with healthy cholesterol levels (175 total and 60 HDL), doesn't smoke, is on blood pressure medication, and keeps systolic pressure at 120 would have a 10-year risk of 1% for heart attack or coronary death.

Those categorized as high-risk using this method have a 10-year risk of more than 20% and a history of heart disease or diabetes.

Testing the AHA Guidelines

Hsia and her colleagues found that 11% of the WHI participants were high risk, 72% were at risk, and 4% at optimal or low risk using the AHA guidelines.