Using data collected from more than 24,000 initially healthy American women, researchers from Brigham and Women’s Hospital (BWH) have devised a new Web-based formula called the Reynolds Risk Score that for the first time more accurately predicts risk of heart attack or stroke among women. In addition to usual risk factors like cholesterol, blood pressure, and smoking, the new Reynolds Risk Score adds information on two new factors: family history of heart attack prior to age 60 and blood level of C-reactive protein (CRP), a measure of artery inflammation. Using the new risk assessment tool, the researchers found that nearly 50 percent of women in the study who were estimated to be at “intermediate risk” for heart attack or stroke based on current guidelines were in fact at significantly higher or lower risk levels.

For the 10 million American women currently classified at “intermediate risk,” use of the Reynolds Risk Score provides doctors and their patients a much clearer picture of who should or should not receive drug therapies such as statins or aspirin, and highlights the critical impact that can be made on heart disease prevention by diet, exercise, and smoking cessation. The findings appear in the Feb. 14 issue of the Journal of the American Medical Association and are available in a user-friendly format for both physicians and their patients at

“Women as well as men suffer premature heart attacks and stroke, but our standard methods for risk prediction have not been as effective in preventing disease among women,” said cardiologist Paul Ridker, the Eugene Braunwald Professor of Medicine at Harvard Medical School, who is director of the Center for Cardiovascular Disease Prevention at BWH and lead author of the study. “One of the problems cardiologists and preventive physicians face is that we often underestimate women’s risk for heart disease and stroke. With the new Reynolds Risk Score, we found many women to be at substantially higher risk than anticipated. That’s an enormous opportunity for prevention because if physicians can accurately tell a woman in her 30s or 40s about true lifetime risk, they’ve got a much better chance of motivating her to stop smoking, get regular exercise, reduce her blood pressure, and where indicated, start a statin or aspirin regimen.”

The Reynolds Risk Score was derived from a study of 24,558 initially healthy women enrolled in the Women’s Health Study in 1992 who were followed more than a decade for the occurrence of heart attack, stroke, and other major cardiovascular events. The researchers first evaluated 35 different risk factors to come up with the best possible prediction tool for clinical use and then directly compared the new prediction tool with traditional approaches currently in use. Two new risk factors proved crucial to understanding cardiovascular risk in these women, each representing an important advance in the biology of heart disease. The first was a simple blood test for C-reactive protein (CRP), reflecting inflammation in the artery wall. The second was whether or not a patient’s parents had suffered a heart attack before age 60, a measure of genetic risk. “When information on CRP and family history were incorporated into our prediction models, they improved the fit and predicted risk more accurately,” said Nancy Cook, the study statistician. “For some women, changes were striking enough to potentially affect treatment decisions or alter behavior,” she continued.

“Using the Reynolds Risk Score, we found that many women were correctly reclassified at high risk, while others had their level of risk reduced,” Ridker explained. “Correctly classifying risk is crucial for those of us trying to get the right preventive drug to the right patient and to do so as cost-effectively as possible. Preventing heart disease among high-risk women while avoiding drug toxicity in low-risk women is a win-win situation for everyone.”

In addition to providing each woman with an estimate of her risk of suffering a future heart attack, stroke, or other major cardiovascular event over the next 10 years, the Reynolds Risk Score Web site simultaneously shows each woman what her risk would be if she improved each of her individual risk factors to optimal levels. For young women, risk may appear low over the next 10 years, yet can be very high over a lifetime. The Reynolds Risk Score also allows each woman to calculate risk as she ages, demonstrating the impact that risk reduction early in life can have on future events. The Reynolds Risk Score Web site provides useful links to prevention programs for women from the National Heart, Lung and Blood Institute, the American Heart Association, and the American College of Cardiology.