Getting to the heart of the matter: Women face cardiovascular risks

Cardiovascular disease kills nearly twice as many women each year as does cancer, yet annual mammograms and Pap smears continue to be an easier sell than lipid profiles or regular blood pressure tests.

Despite years of warnings that women face an even greater risk for cardiovascular disease than men, the word has been slow to filter out. Women and their physicians still don't always acknowledge this threat, nor do they take steps to slow its onset, according to many experts. "It is really important to keep educating patients and physicians about this being such a devastating illness for women," said Norma Keller, MD, chief of cardiology at Bellevue Hospital in New York City.

Figures from the Centers for Disease Control and Prevention illuminate the problem. In 2003, 484,000 women died from cardiovascular disease compared with 427,000 men. Cancer, the next highest killer disease for women, claimed 268,000 lives that same year.

The challenge for primary care physicians is to pick out women most likely to benefit from treatment, said Lori Mosca, MD, MPH, PhD, director of preventive cardiology at New York-Presbyterian Hospital in New York City and chair of the panel that drafted the American Heart Assn.'s Evidence-based Guidelines for Cardiovascular Disease Prevention in Women. "It is clear we are undertreating very high-risk women and that there are many low-risk women who would be better served by lifestyle changes than drug therapy."

So how to determine which group is which? Go back to the basics, she advises.

Evaluating traditional risk factors remains key for primary care physicians, Dr. Mosca said. "We have many physicians who have not discussed with their patients their risk factors for heart disease, including lifestyle and family history." Instead of preventive care, too many physicians are relying on technology that has not been proven to be associated with beneficial outcomes, she added.

Jim King, MD, a family physician in rural Selmer, Tenn., keeps pushing this message to his female patients: "Watch your cholesterol, blood pressure and weight, and don't smoke." He notes that risk factors are the same for men and women, although women's risk starts to increase about 10 years later than men's. His female patients also are still more afraid of breast cancer. "They have to understand that heart disease is a more important threat."

The highest risk

African-American women are at the top of the risk scale for heart disease, but they are the group least likely to be diagnosed and treated effectively, said Patricia Davidson, MD, a cardiologist at Washington Hospital Center in Washington, D.C. "African-American along with Mexican-American and Native American women have more risk factors lumped together." Weight is a problem. Sixty-eight percent of African-American women, 71% of Mexican-American women and 60% of Native American women are overweight, she noted. "With weight gain comes insulin resistance, which leads to diabetes, which raises your blood pressure."

The lack of aggressive treatment to goal is another pitfall, she said. In Dr. Davison's view, goal means a systolic blood pressure lower than 120 and LDL cholesterol levels lower than 100. Even having a systolic pressure of 120 can be serious, she said. Studies have shown the risk of death from heart disease and stroke begins to rise at levels as low as 115 over 75 and doubles for each 20 over 10 mm Hg.

"I think we're setting our goals a little too high," she said. "I have a saying: If you eat animals every day, if your systolic blood pressure is over 120, if your fasting blood sugar is over 100, if your body mass index is over 25, if you don't exercise regularly and your LDL level is over 100, you can't have normal arteries."

Plus, those all-important numbers have been changing. "I'm sure physicians are totally confused as to what kinds of goals they should hope for in the high-risk population," she said. She points to the prehypertension category as being particularly puzzling.

The National Heart, Lung and Blood Institute developed the category in 2003 to include individuals whose pressure was in the 120-139/80-89 mm Hg range. It covers about 45 million American adults and is intended to serve as a warning.

In addition to being at greater risk for cardiovascular disease, minority women are less aware of their plight, Dr. Davidson said. While 60% of white women know that heart disease is a major killer of their gender, only 38% of African-American women and 36% of Latino women are similarly aware, she said.

The key is to help patients turn back their risk factors, she said. "Get everyone to exercise. If you can get patients to start walking, there is a 50% reduced risk for heart attack, stroke and cancer."

While body weight, high LDL cholesterol, elevated blood pressure and a history of smoking are widely accepted as predictors of heart disease, the value for women of the Framingham Risk Score is being questioned.

The score "appears to underestimate risk among several populations of women, especially racial and ethnic minorities and women who have a strong family history of premature heart disease or those with a genetic cholesterol problem," Dr. Mosca said. "And this is a lot of women."

The risk score provides a lot of credit just for being a woman, said Sharonne Hayes, MD, director of the Mayo Clinic's Women's Heart Clinic in Rochester, Minn. "You have to have a lot of risk factors to raise yourself to a higher risk." Dr. Hayes also served on the panel that drafted the 2004 AHA guidelines, which are currently being updated. As part of this process, Dr. Mosca said, the update will focus on the best methods to identify women at increased risk who are most likely to benefit from preventive therapy.

Treating disease

In addition to preventing heart disease, primary care physicians also treat many women who already have symptoms or who may have had a heart attack, Dr. Hayes noted. But unfortunately, there is no mammogram-type screening test for heart disease. "We have to depend on risk assessment and then targeting of those higher-risk people, or those with symptoms, for additional testing," she said.

And it has been known for several years that women's heart attack symptoms may differ markedly from men's -- although Dr. Hayes cautions that women also can have the classic, crushing pain of a "Hollywood" heart attack.

Women can present with fatigue, shortness of breath and palpitation, said Oscar Marroquin, MD, medical director of the Women's Heart Center at the University of Pittsburgh's Magee Women's Hospital.

"When a woman complains of chest pain, or any other vague symptoms, instead of thinking, 'This may be gastrointestinal,' physicians should be thinking, 'Let me make sure it's not the patient's heart,' " Dr. Marroquin said. A reasonable step would be a stress test with imaging, he added.

But the treadmill test on its own produces too many false positives, Dr. Keller noted. "If you add another imaging modality, like a nuclear scan or an echocardiogram and perform it when a woman is at rest and then when she is exercising, the results can be more helpful. It is more expensive, but it's worth it."

A recent finding from the Women's Ischemia Syndrome Evaluation, or WISE study, revealed that standard tests for assessing coronary artery disease might not spot the diffuse buildup of plaque that often forms in the smaller coronary arteries of women's hearts. This buildup could be the reason for the different symptoms experienced by women as well as the poorer outcomes experienced after angioplasty and stenting, said the researchers.

The WISE study also found that factors such as metabolic syndrome, mental stress and depression, smoking and low levels of estrogen before menopause also play a large role in the development of cardiovascular disease among women.

There is mixed evidence as to whether a daily low-dose aspirin protects a woman's heart. Results from the Women's Health Study, published in the March 31, 2005 New England Journal of Medicine, found a benefit in preventing strokes but not death from heart attacks in women. But a study published in the March 22/29 Journal of the American Medical Association determined that aspirin was similarly protective against heart disease in women and men.

Other research suggests that women with heart disease have worse outcomes than do men, but the "why" is still unknown. "We don't know whether women are presenting later because we have not made the diagnosis as soon as we could have," Dr. Marroquin said. "In my mind the take-home message should be, we have not been as aggressive in looking for heart disease in women. We have to do a better job. Hopefully, by doing that, outcomes should start to improve."