Heart Disease: Women's Unique Risks Demand Attention

Numbers Tell the Story

- Coronary heart disease (CHD) kills half a million U.S. women every year

- CHD accounts for 45% of all deaths in women, more than all forms of cancer combined

- The mortality rate from CHD is 69% higher in African-American women than in white women

- 1 in 2 women die of heart disease or stroke; 1 in 25 die of breast cancer

- In the Framingham Heart Study, 63% of women who died suddenly of CHD had no previous symptoms

Source: American Heart Association

“Much of heart disease [in women] gets missed or misdiagnosed,” said Martha Hill, RN, PhD, president of the Dallas-based AHA. “Now, we're learning a lot about the prevalence of heart disease and the benefits of treatment. This statement shares what we've learned.”

Age and Coexisting Conditions

Differences in coronary heart disease (CHD) between men and women contribute to a disparity in the mortality rate. Women tend to develop CHD 7 to 10 years later than men-after menopause, when the cardiovascular benefit of estrogen is apparently lost. Because they present with heart disease at later ages, women are also more likely to have coexisting conditions that can reduce survival.

Women often present cardiac symptoms late, when the disease has progressed. And although women frequently experience the same kind of chest pain as men during a myocardial infarction (MI), they are also more likely to have confusing symptoms of upper abdominal pain, nausea, or fatigue. Finally, basic physiologic differences, such as smaller body size-hence smaller coronary arteries-make bypass surgery more difficult and lead to a higher operative mortality rate.

“All this means that physicians need to recognize that there are unique aspects of heart disease in women,” said Lori Mosca, MD, PhD, a preventive cardiologist at the University of Michigan in Ann Arbor and lead author of the AHA statement. “You need to screen for the disease and then aggressively treat women who are at risk.”

Prevention, of course, is the best approach. Educating all patients-even young ones-about the major risk factors, including smoking, diet, and lack of exercise, remains the essential first step. These factors affect both men and women at roughly the same rate.

Other risk factors disproportionately affect women. Diabetes, for example, raises a woman's risk for CHD three to seven times above normal while causing only a two- to threefold increased risk for men. The reasons for this difference are not known. As with diabetes, a decreased level of high-density lipoprotein is a stronger predictor of CHD in women than in men, and an elevated level of triglycerides may have a more serious consequence for women as well.

Routine Screening

The AHA guidelines recommend routine blood pressure screening every year or two and measurement of both total cholesterol and high-density lipoproteins beginning in a patient's twenties. Risk factor awareness and an ability to recognize warning signs are the keys to prevention and early diagnosis for women, according to the AHA.

Diagnosing heart disease may require different tests for men and women. For example, ordinary treadmill testing may be more likely to yield false-positive results in women than in men (Am J Cardiol. 1995; 75:52D-60D). Instead, the AHA recommends considering the use of stress echocardiography to evaluate possible symptoms of CHD. New imaging techniques, like magnetic resonance imaging or positron emission tomography, are still experimental but may be useful in the future.

Aggressive Treatment

Within 2 years of an MI, 36% of women die, compared with 21% of men. The mortality rate is particularly high in African-American women. Severity of illness, increased age, and more comorbid conditions may all contribute to the higher mortality rate in women. But considerable evidence, including a recent Canadian study, suggests that women receive far fewer tests and less medication after an MI than men do, even when they see a physician just as often (Arch Intern Med. 1997; 157:1545-51).

The AHA recommends that physicians manage heart disease as aggressively in women as in men. “There's no such thing as a touch of high blood pressure,” emphasized Kelly Spratt, MD, a cardiologist at the University of Pennsylvania in Philadelphia. “If you find it, you've got to treat it.” For men and women alike, the medications most commonly used to treat CHD are aspirin, angiotensin-converting enzyme inhibitors, β-blockers, and lipid-lowering drugs.

Preliminary studies suggest that hormone replacement therapy in postmenopausal women lowers the risk for both CHD and stroke. Accordingly, many physicians prescribe estrogen supplements for their female patients, depending on the patient's comfort level with hormone replacement and relative risk for endometrial and breast cancers. The AHA statement, like those from a number of other organizations, supports an approach that weighs the pros and cons of hormone replacement therapy for each woman, considering her health, disease risks, and family history.

The AHA contends that, by applying the most up-to-date knowledge about prevention, diagnosis, and treatment of heart disease, physicians can revolutionize health care for women. “There is more information available than ever before, and physicians are more aware of heart disease's challenges,” Hill said. “That's a step in the right direction.”

-Kathryn S. Brown