A Change of Heart
A new tool alerts women to their hidden risks of heart disease
Heart trouble is often the furthest thing from a woman's mind, even when she can't breathe and her chest hurts like mad. Back in 2002, for example, Carmella Doppelheuer drove to McDonald's for a Big Mac and supersize fries while gripped by awful chest pain. "It just never occurred to me that it was my heart," says the 56-year-old from Carney, Md. She thought it might be a hernia. "God, I even smoked a cigarette on the way to the hospital later that night, can you believe it?" Admitted to the hospital for observation, she had a full-blown heart attack two days later. Leslie Power, 47, of Jamaica Plain, Mass., ignored her chest pain and shortness of breath for several days in 2005 because she thought she was getting asthma. Then she almost passed out driving to work and ended up in a hospital where doctors labored to prop open one of her blocked arteries with a stent. "Women just don't think about their risk of heart trouble," Power says. "Even me, and I'm an administrative assistant to a cardiologist!"
Though groups like the American Heart Association have been campaigning for years to get women to realize they are indeed at risk, Paul Ridker and his colleagues hope they've hit on a more concrete solution. Last week they unveiled a new tool called the Reynolds Risk Score, a seven-item calculator incorporating new risk factors designed to give women and their doctors the most accurate view ever of their heart risk (box, Page 64). If they are heading for trouble, it also tells women how much actions such as quitting smoking will reduce their chances of ending up like Doppelheuer and Power.
Intervene. It seems to do a good job of picking such women out of the pack. When tested on a large population, the Reynolds score took about half of all women marked as at "intermediate risk" by traditional means-a group with between a 5 and 10 percent chance of developing heart problems during the next decade, which doctors have been unsure whether to treat-and reclassified them at higher or lower risk. "This gives us a chance to intervene with lifesaving medications if we need to," says Ridker, a cardiologist and director of the Center for Cardiovascular Disease Prevention at Brigham and Women's Hospital in Boston. "Heart disease is different in women. Yet most of the tools for measuring risk have been developed using men" and so have not worked well for women.
The current dominant tool for estimating risk was developed by the Framingham Heart Study, a federal research project that has studied residents of a Massachusetts town for more than 50 years. But it focused mainly on identifying the factors that led to heart attacks. Those turned out to be things like high cholesterol and blood pressure and a history of smoking. But the emphasis on heart attacks, some critics say, makes it a less accurate predictor for women. Unlike men, who typically first learn they have a problem when their heart seizes up in an attack, women's first sign of heart-related trouble is just as likely to be a stroke, or chest pain caused by blocked arteries that stops short of a major attack. Factors that only forecast heart attacks may not capture the risk of these other problems.
There's grim evidence that methods of identifying and helping women at risk have fallen short. While men's death rates from heart trouble have been dropping for the past quarter century, women's have not. Every year since 1984, in fact, more women than men have died, with the most recent count standing at about 460,000 versus 400,000.
The new tool, described in last week's Journal of the American Medical Association, adds two new elements-family history and levels of C-reactive protein, a marker of inflammation that rises when there is blockage in the arteries-to the mix. "Family history turns out to be a very important predictor for women, perhaps more so than in men, so it's good to have it there," says cardiologist Sharonne Hayes, director of the Women's Heart Clinic at the Mayo Clinic in Rochester, Minn. The protein marker, a recent discovery, is a little more controversial because it hasn't been studied as extensively. But it's gaining more acceptance, says Roger Blumenthal, a cardiologist specializing in disease prevention at the Johns Hopkins University School of Medicine.
What Blumenthal really likes, though, is that the Reynolds score (so named because the calculator development was funded by the Donald W. Reynolds Foundation, which aims to prevent heart disease) predicts not just heart attacks but strokes and all the other cardiovascular problems that affect women more than men. "I think you get a much better picture of women's risks if you include these other things," Blumenthal says. "That's why this is really a landmark study."
In this study, Ridker's group followed about 16,000women for 10 years to determine which of 35 possible risk factors best signaled this broader range of heart problems. Once they identified the most powerful seven to create the Reynolds calculator, the researchers took an additional 8,000 women and ran them through both the Reynolds and the estimator developed by Framingham. About 600 of these women were classified by the older method as being at intermediate risk. But the newer system put about a quarter of those same women at higher risk and about another quarter at low risk. "With the high-risk women you can consider blood pressure medication or aspirin or statins," says Ridker. "And those at low risk you can tell not to worry."
Another new feature of the Reynolds calculator is that it allows women to project their risks up to 40 years in the future. "That's really important for a 40-year-old woman, for example, because typically we don't start seeing heart trouble until the mid-50s or later," Blumenthal says. "So if you just estimate risk at age 40, it doesn't look like there's any problem." But projecting it to age 60 makes the consequences jump out.
Motivation. For instance, a 45-year-old smoker with slightly elevated blood pressure and total cholesterol, slightly low "good" cholesterol, and a C-reactive protein reading that's a little high, has only a 4 percent chance of heart trouble during the next 10 years of her life, according to the Reynolds calculator. But at age 65, if none of these levels change, her risk jumps up to 20 percent. At age 75, it shoots up to 38 percent. "That could motivate one of my patients" to exercise or give up smoking, Mayo's Hayes says. "We all hear we should make lifestyle changes all the time, and we don't. But this might be another little piece of ammunition we can use."
Daniel Levy, current director of the Framingham study, points out that both methods do agree on risk levels in 92 percent of the patients. "So I think you can do a great job with both approaches," he says. And Hayes agrees, up to a point. "You can correctly predict a woman's 10-year risk with Framingham," says Hayes. "But maybe as women we need a longer timeline. Heart trouble does appear later in us. And women do live longer." Her hope is that with refinement like the Reynolds score, more women will get a chance to do just that.
Taking a Calculated Risk
The Reynolds Risk Score for women focuses on seven factors that accurately predicted heart disease in a study of 8,000 women. Plugged into an equation, the numbers are combined to estimate future chances of a heart attack, stroke, or other cardiovascular problem. The factors are:
C-reactive protein. This blood molecule indicates artery damage and inflammation. A score higher than 3 on a test called high-sensitivity CRP means elevated risk.
Family history. A heart attack in either parent before age 60 increases risk.
Age. Women's risk starts to climb sharply after age 60, unlike men's risk, which begins climbing a decade earlier.
Smoking. It multiplies chances of a heart attack or stroke two to four times.
Systolic blood pressure. That's the first number in the reading, indicating the pressure when the heart contracts to pump; a healthy level is under 120.
Total cholesterol. A level under 200 mg/dL, detected in a blood test, lowers risk.
HDL or "good" cholesterol. Levels higher than 50 mg/dL are desirable.
This story appears in the February 26, 2007 print edition of U.S. News & World Report.