Queen of Hearts

Since heart disease in women is difficult to diagnose, has varying symptoms and is more deadly than in men, women need to learn more to stay heart healthy and live longer.

by Jane E. Allen

When a woman experiences shortness of breath, unexplained fatigue or abdominal pain, she is very likely to dismiss those feelings, or attribute them to stress.

She shouldn’t, nor should her doctor.

Those are the top three signs that she is having a heart attack and should be headed for the nearest emergency room.

Mention the phrase “heart attack” and many people conjure up the stereotypical image of a man with an agonized expression on his face, sweating heavily and complaining of crushing, radiating pain as he clutches his hands to the left side of his chest. But a woman having a heart attack is just as likely to have pain in her jaw, neck, arms, right chest, upper back or upper abdomen, and to be nauseated, have trouble breathing or complain of feeling totally exhausted.

Medical students and young residents being trained today are taught that, in women, these atypical symptoms can be important signs of heart trouble, and that they should order appropriate diagnostic tests. The message is reaching physicians in emergency rooms of research hospitals and major medical centers, but further education is needed among general practitioners, family doctors and internists.

“It has to be drilled into people’s minds,” says Padmini Varadarajan, M.D., a cardiology fellow at the Keck School of Medicine of USC, whose residency training in the late 1990s incorporated awareness about heart disease in women. But, she says, this awareness has not yet trickled down to the general population—something that the American Heart Association has been trying to do with its current “Go Red” educational campaign. “Women tend to be in denial. They don’t recognize the symptoms,” Varadarajan says. “It is a lack of education about how women are affected by heart disease.”

Education is crucial because cardiovascular disease is the top killer of women: 1 in 2 currently die either of heart disease or stroke, according to American Heart Association figures. More frightening still is that “approximately 60 percent of women, when they have a heart attack, die suddenly,” says Howard N. Hodis, M.D., the Harry J. Bauer and Dorothy Bauer Rawlins Professor of Cardiology and director of the USC Atherosclerosis Research Unit. “Their first symptom is death. In men, it’s about 48 percent.” Among heart attack survivors, he says, more women die within the first year than men.

Little hearts

“We have to stop thinking about how we get women to fit into the men’s mold,” says Nieca Goldberg, M.D., author of the 2002 book about women and heart disease, Women are Not Small Men. For many years, physicians assumed women’s hearts were simply smaller versions of men’s, and that whatever tests or treatments worked for a man would work for a woman.

Women’s hearts indeed are smaller. As a result, their blood vessels are inherently narrower and more easily blocked with a smaller amount of plaque—the fatty, sticky deposits that accumulate inside artery walls.

The differences between men’s hearts and women’s hearts manifest themselves in their vulnerability to various types of heart disease, in the effectiveness of diagnostic tests, and in their responses to medications. Some doctors suspect women are more likely to have so-called unstable or vulnerable plaque deposits, which are more prone to rupturing and then clogging a blood vessel. The smaller size of women’s hearts makes it harder to interpret cardiac imaging tests. Their smaller-on-average body size also means they need lower doses of medications than men. Even side effects differ: A recent study found that women taking blood pressure-lowering drugs called angiotensin-converting enzyme (ACE) inhibitors were more likely than men to experience a medication-related cough.

Women also are less apt to receive appropriate treatment, as exemplified in chilling stories of women sent home from doctors’ offices or emergency rooms—only to learn later that they had suffered a heart attack.

Similarly, otherwise healthy women with a heart rhythm problem called superventricular tachycardia, which makes their hearts race, are sometimes mistakenly told they are suffering from panic attacks, says Leslie Saxon, M.D., Keck School professor of cardiovascular medicine and director of electrophysiology at USC University Hospital. “The symptoms are very similar: a feeling of dread, lightheadedness, palpitations, nearly fainting. Women get put on antidepressants all the time for superventricular tachycardia. But they don’t get better.”

Saxon calls this scenario the most classic case of gender discrimination in her field. The irony, she says, is that the condition can be identified and permanently cured with radiofrequency catheter ablation, a procedure that entails snaking a catheter into the heart and ablating or creating a small lesion in the heart tissue at the area responsible for the problem.

Women have at least one inherent advantage over men in the cardiovascular realm: They tend to develop heart disease about 10 years later than men. Doctors suspect that protection stems from hormonal differences—namely the production of estrogen until menopause, which typically occurs around age 50. Estrogen improves levels of blood fats as well as the condition of blood vessels.

After menopause, however, a woman becomes as prone to heart disease as a man, and if a woman is diagnosed in her later years, the plaque in her arteries may contain more calcium and be harder, which is a factor of age, says Alex Durairaj, M.D., assistant professor of cardiovascular medicine at the Keck School, who performs invasive cardiac procedures. Plus, in later years, he says, a woman is likely to have developed other diseases that may complicate her treatment. Hodis, who also is a Keck School professor of medicine and preventive medicine, is currently conducting a federally funded study to look at how hormones can be given to women for the prevention of heart disease (see related story on page 24).

But all that inherent hormonal protection can be erased by diabetes, one of the most potent contributors to heart disease. Women with diabetes are at a significantly higher risk of dying from coronary heart disease than men with the condition, which impairs the ability to make and use the insulin required to turn sugar into fuel for the brain and body.

Different tests

The traditional diagnostic tests used to detect heart disease in men do not necessarily work for women. An electrocardiogram (EKG), which picks up erratic heartbeats or rhythms, and an angiogram, which uses dyes to capture a picture of what is happening in the arteries, are likely to miss important sources of chest pain in women.

Stress tests conducted while a woman walks or runs on a treadmill often produce false positives, suggesting blockages that do not exist, even though the heart may have real abnormalities, such as an inability of the pumping chamber known as the left ventricle to relax properly after contracting, Varadarajan says.

Instead, a woman should be given a stress test along with another test that creates an image of the heart’s structure, such as an echocardiogram, which uses ultrasound, or a test that uses nuclear dyes to see which areas of the heart are not receiving enough blood during exercise. And, says Varadarajan, doctors today also can examine blood flow through the heart with non-invasive tests such as magnetic resonance imaging (MRI) or single photon emission computed tomography (SPECT).

Even when women have heart blockages, they are less likely to receive treatment. Only one-third of the 1.2 million annual procedures used to open up clogged coronary arteries are performed on women, even though women and men suffer similarly from coronary artery disease. Despite a perception that women do not derive similar benefits from treatment, a study published in the April 18 issue of the Journal of the American College of Cardiology found that women respond as well as men to drug-releasing stents—the mesh cylinders that are inserted into newly unclogged arteries to prop them open and release medications to inhibit re-clogging, or restenosis.

One fundamental problem with the state of knowledge about women’s hearts is that most of what physicians have known or thought they knew was based on clinical trials conducted on men. Women remain underrepresented in trials documenting the effectiveness of devices such as implantable cardiac defibrillators in preventing sudden death, Saxon notes.

But, “we’re gradually learning,” says Gerald Pohost, M.D., professor of medicine and chief of the division of cardiovascular medicine at the Keck School. He notes that the learning process has been fueled in recent years by the recognition that “women were dying of heart attacks much more commonly than ever imagined.”

A significant amount of new information has come from important research studies such as the federally funded Women’s Ischemia Syndrome Evaluation (WISE) study. It examines ischemia—a lack of blood flow through arteries that normally deliver oxygen-rich blood to the heart.

When Pohost arrived in Los Angeles from the University of Alabama-Birmingham about four years ago, he brought with him ongoing WISE research into what is called chest pain syndrome.

For years, chest pain, or angina, had been thought of as dull, persistent pain beneath the breast bone that radiated into the left shoulder and neck. It could be relieved with nitroglycerin tablets slipped under the tongue, which helped relax constricted arteries. But in many women, angina did not occur in the same way as in men. Pohost and his co-investigators found that something else is happening in women who had chest pain but whose angiograms do not show significant blockages.

This is of concern because about 50 percent of women who undergo angiograms do not have major blockages, compared with perhaps 5 to 10 percent of men who undergo the same cardiac tests.

The remaining 50 percent of women—those whose angiograms show classic coronary artery disease—are more likely to die from it than men. Still, researchers cannot yet say whether that is because by the time a woman has symptoms, the disease is more advanced, or whether women have simply endured and ignored the same amount of pain that would typically send a man to the doctor.

Further complicating the diagnosis is that even when radioactive dyes are used, the low resolution of the images, combined with women’s inherently smaller hearts, makes it even harder to see blockages, Pohost says.

Using a technique called spectroscopy, which measures levels of phosphorus compounds in the heart during periods of rest and stress, Pohost and his colleagues showed that even in women without big blockages, too little blood was flowing to the heart muscle. The researchers concluded that most of these women suffered from microvascular disease—abnormalities in small blood vessels—which prevents blood from flowing properly through the heart.

Today, at the Keck School of Medicine, Pohost is using more powerful spectroscopy to better measure chemical changes taking place in the hearts of women with chest pain syndrome. The goal is to determine how to treat the underlying problem.

Protect yourself

Physicians agree that the best way to beat heart disease is to prevent it in the first place, which can be done by adopting heart-healthy habits. That means exercise regularly, preferably five times a week. Eat plenty of nutrient-rich fruits and vegetables, which contain such heart-healthy compounds as antioxidants. Cut out the saturated fats found in butter and red meat. Switch to low-fat dairy products and get protein from fish, poultry and lean meats. Eliminate the trans fats in margarine and many baked snacks and switch to healthier fats found in olive oil, avocados and nuts. Watch blood pressure readings, aiming for 120/80 or less. Aim for levels less than 100 for low-density lipoprotein (LDL), the so-called bad cholesterol, and over 60 for high-density lipoprotein (HDL) or good cholesterol. And finally, get the message: Quit smoking.

In addition, experts say people over the age of 40 should ask a physician about taking a low-dose daily aspirin to prevent stroke and heart attack, although caution should be taken since gastrointestinal bleeding can occur. Studies have shown the benefits of aspirin therapy vary by gender; it is more likely to prevent heart attacks in men and more likely to prevent strokes in women.

Here is some other heartening news. Several studies have now demonstrated that the size and strength of women’s social support systems significantly benefit cardiac health. A federally funded study published in the journal Psychosomatic Medicine in December 2004 found that among 503 women with suspected coronary artery disease, those with larger social networks had a lower risk of suffering a heart attack or stroke and lower rates of dying from heart disease.

Another recent study found social support may be a key element in getting women with heart disease to stick with an exercise program, which can lower risks and improve heart function.

As the awareness of women’s unique cardiac needs grows, the way to assure they are properly addressed may come down to more than just education and communication.

Says Saxon: “A lot of us working in the field think that the ultimate answer is (having) more women in the field of cardiology.” ??

Jane E. Allen is a freelance writer based in Los Angeles.

For more information about cardiac care, or to learn more about The Doctors of USC, call 1-800-USC-CARE.