UNTIL RECENTLY, THE PUBLIC AND MOST HEALTH care professionals shared the misperception that cardiovascular disease (CVD) primarily affects men. Many women with CVD don't exhibit the signs and symptoms identified in early research on men, so CVD was considered less dangerous for women; consequently, women typically received less aggressive diagnostic workups and treatment. But as researchers became aware that women respond uniquely to many other diseases, they started taking a sex-based approach to studying CVD as well. Their discoveries have revolutionized the way women at risk are assessed and treated.
In this article, we'll look at the recently updated American Heart Association (AHA) guidelines for preventing CVD in women, and compare signs and symptoms, diagnostic needs, and responses to therapies with those in men. We'll also help dispel long-standing myths about CVD in women.
Equal-opportunity killer
According to the AHA, heart disease is the leading killer of men and women in the United States and the second leading cause of death in most developed nations.1 Cardiovascular disease, which includes acute coronary syndromes, atherosclerosis, and other forms of chronic ischemic heart disease, is responsible for many of the deaths.
As you know, a patient's risk factors for CVD fall into two categories: Those that can't be modified, and those that can. You'll use these factors to determine a woman's risk for CVD (see Determining Your Patient's CVD Risk). Risk factors that can't be modified are:
* Sex. The rates of diagnosis and death due to CVD among women are holding steady; the rates for men are declining. In fact, more than 500,000 women die of CVD each year-that's more than the number of CVD deaths in men and the next seven causes of death in women combined.1
* Age. Men develop CVD at younger ages than women, but the incidence and prevalence equalize between both for women after menopause.1 Although many sex-specific differences in CVD remain a mystery, postmenopausal status is widely considered an independent risk factor, so recent research has focused on whether estrogen has a cardioprotective effect.Surprisingly, studies have shown that postmenopausal women on hormone therapy with estrogen alone or estrogen and progestin had increased rates of thrombolytic events such as myocardial infarction (MI) and stroke, as well as breast cancer.2 Because of these risks to women, the AHA no longer recommends hormone therapy to prevent or manage CVD for postmenopausal women. However, clinicians may still prescribe short-term hormone therapy to treat menopause symptoms, such as hot flashes and vaginal dryness. Estrogen alone may provide benefits, although it's not safe for women with an intact uterus.2
* Ethnicity. We don't know exactly why, but race and ethnicity together affect the risk of CVD. Access to care, detection, genetics, and lifestyle all may be involved. The death rate for African-American women with CVD is almost 40% higher than that of white women. The death rate among Mexican-American and white women with CVD is about the same.1
* Genetics. Cardiovascular disease has a strong genetic component, and inherited susceptibility patterns appear in families.
Identifying other risks
Now let's look at the CVD risk factors that you can help your patient identify and modify. Although these factors jeopardize both men and women, they may contribute to a poorer prognosis in women. By themselves, diabetes and hypertension are especially strong predictors for CVD and are associated with a poor outcome.
* Diabetes poses a greater risk than any other factor. In the Nurses' Health Study (an ongoing investigation of risk factors for major chronic diseases in women), women with diabetes had seven times more cardiovascular events than other women and about half of them died of CVD.3Women with diabetes and CVD, especially Hispanic and African-American women, die at a much higher rate than men or nondiabetic women with these conditions. Young women with diabetes lose any premenopausal protection, so their risk of developing CVD equals that of men their age.
* Hypertension, especially if it develops before menopause, puts a woman at a much greater risk of CVD than women or men with normal blood pressure (BP). At least half of women may have hypertension before they reach menopause, with the prevalence greatest in African-American women. Elevated BP is two or three times more common in women who take oral contraceptives, especially older women who are overweight.1 Because hypertension commonly develops with aging, CVD is a significant concern in older women.
* Smoking even a few cigarettes a day correlated with a greater risk of CVD or fatal MI, according to the Nurses' Health Study.4,5 About a quarter of all women smoke, with the prevalence greatest among postmenopausal women. A lifetime of smoking puts a woman at a greater CVD risk compared with a man who doesn't smoke. Younger women who smoke probably cancel out any premenopausal CVD protection. Women who take oral contraceptives and smoke are more likely to have an MI or stroke than those who take the pill but don't smoke.
* Dyslipidemia doubles a woman's risk of CVD compared to women with normal lipid profiles, according to the Framingham Heart Study (ongoing since 1948). Other recent studies have shown that low levels of high-density lipoprotein (HDL) are a much stronger predictor of CVD mortality in women than men.6
* Obesity is another key risk factor. Central obesity poses an even greater risk than increased body mass index (BMI). A healthy waist circumference is less than 35 inches (87.5 cm) in women and less than 40 inches (100 cm) in men; the desired BMI is 18.5 to 24.9 kg/m2 for both sexes.
* A sedentary lifestyle can contribute to obesity, dyslipidemia, hypertension, and hyperglycemia. Exercise can reduce cardiovascular risk by increasing HDL levels and decreasing BP, blood glucose, and low-density lipoprotein (LDL) levels. Exercise can cut a woman's CVD risk by half and may significantly decrease the risk of a second MI in a postmenopausal woman who's already had one. Research indicates that a woman needs 30 minutes of moderate-intensity physical activity (such as walking) on most if not all days of the week, to decrease her risk.7 However, women who need to lose weight or sustain weight loss should engage in at least 60 minutes of moderate-intensity physical activity (such as brisk walking) on most if not all days of the week.
* Stress puts a woman at greater risk of developing CVD and at greater risk of poor outcomes, according to several studies.8,9 Depression also may increase a woman's risk of a cardiac event or deter her from seeking medical help. Consider screening women with coronary artery disease (CAD) for depression, and refer them for treatment when indicated.7The risk factors for CVD seem to have a synergistic effect, so the more of them your patient reduces or eliminates, the better her chance of preventing problems. In simple language, teach her about all the risk factors and explain how to modify those she can change.
His 'n' hers signs and symptoms
Numerous studies have shown that women and men with CAD differ in the way their illness first becomes apparent, but the reasons aren't well understood.
Many men are unaware that they have CVD until they develop typical symptoms of acute coronary syndromes (MI or angina). Women, on the other hand, are more likely to see their primary care providers because they've been experiencing more subtle symptoms, such as shortness of breath, fatigue, or changes in sleep patterns. Because clinical presentations may be "atypical" in women, their symptoms may be overlooked or considered unrelated to CVD.
The classic pain of CVD-more commonly experienced by men-is substernal pain characterized by a heavy, crushing, or squeezing feeling commonly occurring with physical exertion or emotion. If ischemia is causing the pain, rest and treatment with sublingual nitroglycerin can relieve it. If the patient is having an MI, pain can occur at rest and can be relieved only by nitroglycerin, morphine, and reperfusion therapy such as percutaneous coronary intervention (PCI).
In women, the discomfort of CVD varies greatly and may be more generalized or subtle. A woman may describe heaviness, squeezing, or pain in her left chest, abdomen, midback, or shoulder. If she doesn't have chest pain, she may have arm pain. She may have palpitations or pain she describes as sharp or fleeting, but it may return.
A woman with angina may have chest discomfort during rest or sleep or with other symptoms during exertion. During an acute MI, discomfort is more likely to occur in her neck, back, arm, shoulder, jaw, or throat, possibly accompanied by symptoms such as nausea and vomiting, indigestion, upper abdominal pain, dyspnea, fatigue, diaphoresis, dizziness, or fainting. An older woman or one with diabetes may not experience any pain during an MI.
Significantly, electrocardiogram (ECG) findings are different for men and women. A woman experiencing an MI is far less likely than a man to have concurrent ST-segment elevation. If she describes atypical pain and has an ECG that doesn't show any ST-segment changes, she may be misdiagnosed and not get follow-up testing.
Diagnostic testing: Doing the right thing
Anyone who's experiencing symptoms that suggest acute coronary syndromes should immediately go to the emergency department and be triaged according to the American College of Cardiology (ACC)/AHA classification guidelines as described earlier.
If your patient isn't having acute chest discomfort but may be at risk for CVD, conduct a risk assessment using the Framingham tool. Because of improvements in technology used to identify CVD in its earliest stages, health care providers are beginning to recognize a CVD continuum of risk rather than a "have or have not" condition. Depending on your patient's risk assessment, her health care provider may order stress testing, echocardiography, or cardiac catheterization to rule out CVD or evaluate its extent and severity.
If your patient is classified as at risk or high risk for CVD, she should undergo an exercise or pharmacologic stress test, according to the ACC/AHA guidelines. Unfortunately, false-positive results for these tests are more common in women than men. Even though administering a radioisotope such as thallium greatly increases the test's sensitivity, it's less specific and less useful for identifying CVD in women. Exercise echocardiography ("stress echo") is an alternative diagnostic test that's more reliable for detecting CVD in women, especially when wall motion or valve function is in question.
Research suggests that anyone with a positive or inconclusive stress test or stress echocardiogram should undergo cardiac catheterization with coronary angiography. Coronary angiography is the most reliable diagnostic tool in women. However, it's an invasive procedure that poses a greater risk of bleeding, infection, and stroke and isn't indicated unless CVD is strongly suspected.
Other diagnostic methods for CVD that are under investigation include electron beam tomography, three-dimensional magnetic resonance imaging, and positron emission tomography.
Teach your patient about the diagnostic tests for CVD, encourage her to discuss any concerns with her primary care provider, and advocate for more testing or referrals if assessment findings suggest CVD.
Helping your patient make changes
If your patient has risk factors for CVD or is diagnosed with CVD, help her modify the risks that affect disease progression (see An algorithm for CVD preventive care in women). According to the AHA, comprehensive assessment and reduction of contributing factors can extend survival, improve quality of life, and reduce the incidence of subsequent coronary events and the need for invasive procedures.
Lifestyle modifications are the cornerstone of preventing and managing diabetes, hypertension, dyslipidemia, and obesity. Teach your patient about these recommendations from the AHA:
* Eat a low-fat, low-cholesterol diet and avoid saturated fats such as butter, cheese, and fatty meats. Limit daily saturated fat intake to less than 10% of calories, cholesterol intake to less than 300 milligrams, and limit intake of trans fatty acids. Recent research shows that omega-3 fatty acids found in oily fish such as tuna and salmon protect against CVD, so eat these fish several times a week. (However, pregnant or lactating women should avoid fish that are potentially high in methylmercury, such as swordfish and king mackerel.)
* Eat more fresh fruits, vegetables, whole grains, and other foods high in fiber. The recommended daily fiber intake is 20 to 30 grams.
* Limit salt intake to 2,400 mg/day.
* Limit alcohol consumption to one drink per day. One drink is a 12-ounce bottle of beer, 5-ounce glass of wine, or 1.5-ounce shot of 80-proof liquor.7
* Get at least 30 minutes of moderate aerobic activity (such as walking) daily.
* If you're overweight, lose weight to maintain your BMI at less than 25 kg/m2 and your waist measurement less than 35 inches.
* If you have diabetes or prediabetes (elevated blood glucose levels that will progress to diabetes without treatment), keep your blood glucose level in the normal range and your hemoglobin A1C level at less than 7%.
* If you smoke, stop. Whether or not you smoke, limit secondhand exposure to smoke.
* Reduce stress through lifestyle modifications.
Although making these changes can significantly improve your patient's prognosis, she may need more than lifestyle modifications to manage all of her risks. To manage prediabetes, diabetes, or hypertension, she may need one or more medications. If her lipid levels aren't normal, her health care provider may recommend treatment with a statin, alone or in combination with another drug.
Drugs commonly used to manage CVD are
* antiplatelet agents such as aspirin and clopidogrel, which help prevent thromboembolic events
* statins such as atorvastatin and pravastatin, which help normalize lipid levels, reduce rates of nonfatal MI and stroke, and decrease the need for PCI or coronary artery bypass grafting (CABG) surgery.
* beta-blockers such as metoprolol, which reduce the risk of MI, reinfarction, and sudden cardiac death
* angiotensin-converting enzyme inhibitors such as lisinopril, which reduce morbidity and mortality in patients who've had an MI and in those with hypertension, left ventricular dysfunction, or diabetes.
* short-acting sublingual or aerosol nitrates, which reduce acute angina symptoms
* long-acting nitrates, such as nitroglycerin, which prevent angina and improve exercise tolerance.
If your patient has coronary artery stenosis, she may need an invasive procedure such as PCI or CABG surgery. Because a woman's blood vessels may be small and difficult to cannulate or visualize during such a procedure, her risk of complications is greater. Women are more likely than men to experience bleeding at the surgical site or hemorrhagic stroke, and their in-hospital mortality rate is significantly higher.
Rehabilitation for recovery
When a woman has had a cardiac event, her prognosis is poorer than a man's. Women who've had an MI have higher hospital readmission rates for unstable angina, reinfarction, heart failure, ventricular tachycardia, and ventricular fibrillation.10
The main goals for anyone who's had an MI or a revascularization procedure are to reduce risk and restore functional capacity. Follow-up care should focus on the patient's signs and symptoms, energy level, blood cholesterol levels, medication use, and ability to cope with daily stressors. Formal rehabilitation after an MI, PCI, or CABG surgery includes early ambulation, behavioral modifications, psychosocial support, and vocational and sexual counseling.
Literature about women in cardiac rehabilitation is scarce. We know that women participate less than men, yet strong anecdotal evidence suggests that patients of both sexes respond well to rehabilitation. Why they participate at different rates is unclear. Possibly women don't commonly receive referrals, or they're sent to rehabilitation programs that don't meet their needs.
Empowering women against a killer
Cardiovascular disease, though largely preventable, remains the number one killer of women in the United States. As a nurse, you're in an ideal position to explain its grave significance to women, teach prevention, and alert them to their unique responses and needs. With your help, more women will learn what it takes to empower themselves against this killer.
At the Harris College of Nursing and Health Sciences at Texas Christian University, Dennis Cheek is the Abell-Hanger Professor of Gerontological Nursing, Melissa Sherrod is an assistant professor, and Jennifer Tester is a nursing student and research assistant.
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