Basic Facts
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One in four women dies from CHD, making it the #1 killer of women, regardless of race or ethnicity.
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While more women today understand that CHD is the leading killer of men and women, most women fail to make the connection between risk factors and their personal risk of developing CHD.
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More women (52%) than men (42%) die from a heart attack before reaching the hospital.
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Two-thirds of women who suffer a heart attack never fully recover.
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One in three adult females has some form of cardiovascular disease
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Women who are obese, physically inactive, older than 65 years, of certain ethnicities, have high blood pressure or high cholesterol levels all have a greater risk of developing CHD, as do women with diabetes or pre-diabetes
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Numerous medical tests can help determine whether a person has CHD, but the effectiveness of individual tests varies by sex of the participant
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The relationship of birth control and hormone therapy to CHD is not fully understood and should be discussed with your physician
Healthy diet, physical activity, and weight loss can help control or prevent CHD along with medication.
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Background
Not too long ago, CHD was considered predominantly a man’s disease. Men were the breadwinners and their hard work sometimes led to chest pain and heart attacks. Women, on the other hand, had “female problems” and CHD was not one of them. When women reported symptoms that would have been considered signs of CHD in men, their complaints often were dismissed as meaningless or even fictitious.
The ongoing National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study has helped explain why detecting CHD in women is more challenging. One-half of women with symptoms of CHD have no apparent obstruction of coronary arteries, yet these women — perhaps 1 million each year — have persistent symptom-related disability. These are the women who, until fairly recently, were most at risk of being told their problem is in their head, not their heart.
If it’s not blockage of the arteries causing the chest pain known as angina, what is the problem? About one-third of these women have a problem in the cells that line the inner surface of all blood vessels (the endothelium). When these cells don’t function properly, the result can be microvascular coronary disease related to endothelial dysfunction, a key event in the development of CHD. Microvascular coronary disease and endothelial dysfunction can be caused by a large number of factors, such as hypertension, high cholesterol levels, or diabetes, as well as from environmental factors, such as from smoking.
Among the two-thirds of women without endothelial dysfunction and no evidence of ischemia, there are other problems that might cause chest pain, including esophageal reflux, gallbladder disease, etc.
Gender differences
When it became apparent that women do develop CHD, the general assumption was that the same treatments that were effective in men should simply be applied to women, too, despite the fact that these treatments emerged from studies done largely or even exclusively in males. Indeed, from 1977 to 1993, women of childbearing age were excluded from the early phase of clinical studies; the federal mandate was meant to “protect” women and their future offspring. Yet, older women often were largely overlooked, too, when clinical trials were enrolling patients. For example, through the 1980s and 1990s men made up three-quarters or more of all patients enrolled in trials evaluating therapies for treating heart failure.
Also, while women were though to benefit from treatment the same as men, the therapy given women was often inferior to that offered to men. In a study published in 1987, among 390 patients referred for exercise testing, men were much more likely to be referred for invasive testing and treatment compared to women — 40% versus 4% — even when both showed the same abnormal diagnostic test results. Women were four times as likely as men to be given a psychiatric diagnosis to explain their CHD symptoms.
The situation changed with a milestone report published in 2001: “Exploring Differences in the Biological Contributions to Human Health: Does Sex Matter?” The U.S. Institute of Medicine analysis confirmed a pervasive gender bias in medical research and experts insisted that sex differences be considered when designing and analyzing research studies in all areas and at all levels of medical and health-related research
Subsequent studies suggest notable differences between men and women with CHD. There are differences in mortality: 64% of women (versus 50% of men) who die suddenly from CHD do not have classic warning symptoms of an imminent heart attack. Moreover, 38% of women (versus 25% of men) die within 1 year following a heart attack.
More recently, it was shown that while in-hospital rates of death from heart attacks (more accurately called myocardial infarction or MI) are about equal overall for women and men, women are more likely to die if the attack is a more severe type, known as ST-elevation MI (or STEMI). The researchers also determined that various recommended treatments are delayed and underused in women who are less likely to receive early aspirin, beta blockers, reperfusion therapy to restore blood flow, or urgent angioplasty to open an obstructed blood vessel in the heart.
While progress is being made, women today still have a slightly higher cardiovascular mortality rate than men. Surprisingly, while the mortality trend for men with cardiovascular disease has been falling since 1980, women showed increasing cardiovascular mortality until 2000 when rates among women finally started to fall.
The bottom line: CHD is the leading cause of death for both men and women in the U.S. and in most developed countries of the world. It needs to be taken seriously in terms of prevention and treatment by individuals of both genders.
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By the Numbers
In every year since 1900 (except for 1918), cardiovascular disease (CVD) accounted for more deaths in the U.S. than any other cause and more women than men die every year of CVD (including both heart attack and stroke). According to the National Heart, Lung, and Blood Institute, CVD is the #1 killer of women regardless of race or ethnicity. At every age, more women in the U.S. die from CHD than from cancer. Specifically, nearly 60% more women die of CVD (both CHD and stroke) than from all cancers combined.
When a heart attack occurs, more women than men die before they reach the hospital. This may be due to the fact that women are more likely to have more nonspecific symptoms than men, so women may be less likely to recognize when they are having a heart attack. Two-thirds of women who have a heart attack never completely recover and those who do survive their heart attack are more likely to die during the first year than men who have a heart attack.
One piece of positive news — in a 2006 survey, 57% of women polled knew that CHD is the leading cause of death among women, a substantial increase over previous surveys. However, awareness is much greater among white women than among black or Hispanic women, pointing to a greater need for education among minority women.
Whatever their age or ethnicity, women need to learn more about the risk factors, sign, and symptoms of CHD and heart attack.
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Risk Factors
CHD is an all-encompassing term covering a broad set of diseases with no single cause. What causes a healthy heart to become diseased can be attributed to numerous factors — everything from a lifestyle of over-eating and inactivity to having any of several diseases of childhood that begin to weaken the heart in early years to a genetic or familial predisposition to CHD.
All people have varying levels of risk for developing CHD; some risks can be modified, while others cannot. In general, risks that can be targeted and improved upon are those associated with lifestyle choices: overweight/obesity, diet and nutrition, cholesterol and triglyceride levels, degree of physical activity, smoking, hypertension (high blood pressure), diabetes, stress levels, and alcohol consumption. An estimated 70% of all deaths related to cardiovascular disease are due to such modifiable risk factors.
Other risk factors cannot be changed, including increasing age; previous heart attack; and heredity or family history, because those individuals with a close blood relative with CHD are more likely to develop CHD. Women who have had one heart attack have a high risk of experiencing a second one — 43% of women surviving an MI who are 40 years or older will die from a second attack or underlying CHD within 5 years. Ethnicity also is a factor: black and Asian women have a greater risk of developing CHD (and stroke) than white women and there appears to be greater risk as well among other races. Racial and ethnic minority women also have higher mortality rates at younger ages than do white women. Part of this may be due to a higher prevalence of diabetes among minority women. Also, there are important issues relating to access to information and care for minority women.
Gender itself imposes risk, too. Beyond those already mentioned, more women than men will have a second MI within 6 years of the first; women with diabetes are 3 to 4 times more likely than men to develop CHD; and diabetes itself doubles the risk of a second MI in women.
Estrogen
One factor that also impacts a woman’s risk of CHD is that of hormones. The hormone estrogen, which is present in women who are ovulating, is considered heart protective when it is produced naturally by the ovaries. Its introduction into the body by artificial means is the subject of much controversy. Women under the age of 35 who are generally healthy and take estrogen-based oral contraceptives or use a birth-control patch are not likely to experience any increased risk of developing CHD. However, women over the age of 35; women with high blood pressure, diabetes, or high cholesterol; and women who smoke increase their risk of CHD with birth-control pills or the patch (which actually may expose you to more estrogen than the contraceptive pill).
What’s more, for years, postmenopausal women were prescribed hormones to replace those the ovaries no longer produce to counteract hot flashes and other changes in their bodies as well as protect against endometrial cancer and osteoporosis. Hormone replacement therapy (HRT) can help with some symptoms of menopause, including hot flashes, vaginal dryness, mood swings, and bone loss, but there are risks, too. Beginning in 1991, the Women’s Health Initiative (WHI) was undertaken to look at the most common causes of death, disability, and poor quality of life in postmenopausal women — CHD, cancer, and osteoporosis — and involved nearly 162,000 generally healthy postmenopausal women in a series of trials that looked at hormone replacement therapy, now called postmenopausal hormone therapy (PHT).
Some women received estrogen-only therapy and when compared to women with similar characteristics who took placebo pills, the hormone was shown to increase the risk of blood clots and strokes, make no difference in risk of heart attack or colorectal cancer, had an uncertain impact on breast cancer, and reduced the risk of fracture. However, when the women taking estrogen plus progestin were compared to a group taking only placebos, PHT increased risk of heart attack, stroke, blood clots, and breast cancer, while reducing the risk of colorectal cancer. Fewer fractures were seen with the combination therapy as well.
The WHI’s extensive size caused health care professionals to reconsider standard PHT for postmenopausal women. The thought that PHT protected against CHD was dispelled, and the U.S. Food and Drug Administration (FDA) now states that PHT should not be taken to prevent CHD. The therapies tested in the WHI are approved for relief from hot flashes and other symptoms of menopause. However, even though PHT was shown to be effective in combating post-menopausal osteoporosis, it should only be used by women who have a high risk for that disease who cannot take non-estrogen medications. If PHT is prescribed, the FDA recommends women should take the lowest doses for the shortest amount of time possible to reach treatment goals.
Even though the estrogen-progestin trial was stopped due to the health risks seen, researchers continued to follow the participants to determine whether there were long-term risks to the therapy. At 3 years, the women who had taken the combination therapy no longer had increased cardiovascular risk over those participants who had taken placebo pills, but the benefits regarding colorectal cancer and fractures also disappeared.
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Signs and Symptoms
Recognizing the signs and symptoms of CHD is critical. Approximately 64% of women (as opposed to 50% of men) who die suddenly from CHD did not have any classic warning symptoms.
Most people are aware of the classic symptoms of heart attack: chest pain (a painful, crushing feeling behind the breastbone), tingling down the arm (usually the left arm), accompanied by shortness of breath, profuse sweating, light-headedness, and sometimes cold or chill. However, these are more common in men with CHD.
Women often experience less specific symptoms and this may be one reason why more women than men with a heart attack die before they reach a hospital. Women are more likely to have other warning signs, such as pain in the back, neck, jaw or stomach; shortness of breath; and nausea, indigestion, or vomiting. Women also may complain of heartburn, coughing, loss of appetite, or heart flutters. Chest pain called angina may also be a sign of CHD (as opposed to an acute heart attack), as well as new fatigue, insomnia, malaise, or even anxiety. Clearly, women should learn ALL the signs of CHD and heart attack.
Since CHD is progressive — that is, it gets worse over time — symptoms initially may appear infrequently or they be so mild as to be dismissed. However, as CHD becomes more severe, so too do the signs and symptoms of CHD.
Fortunately, studies suggest that women tend to have better body awareness overall than men. Thus, if more women are going to get life-saving care, it’s critical they learn the signs and symptoms of heart attack. Here’s why: A study from the National Institutes of Health (NIH) found that about 95% of women could tell that they were feeling new or different physical symptoms a month or so before a heart attack. Most of these women, unfortunately, didn’t link the changes they were feeling to their impending heart attack. The most common early symptoms included unusual fatigue, sleep disturbance, and shortness of breath. Fewer than 30% of the women had chest pain leading up to their heart attack and 43% had no chest pain even during the attack.
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Testing and Diagnosis
Framingham Risk Score
If CHD is suspected, testing is necessary to determine the type and extent of the disease. What about women with no symptoms? During a routine physical, physicians will assess risk to see if a particular patient merits testing. One way to assess risk is the Framingham Risk Score, which weighs various risk factors, including age, smoking, blood pressure, and cholesterol levels, and the final score determines whether an individual is at low, intermediate, or high risk of cardiac death or heart attack. (If you know your blood pressure and cholesterol levels, the CardioSmart risk calculator is available
here
.) While widely used, keep in mind that the Framingham Risk Score is considered by some experts to underestimate risk in women.
Electrocardiogram (ECG) stress testing
Women with no symptoms and at low risk of CHD are not usually candidates for further testing, but many women will undergo a simple electrocardiogram (ECG) test. This is often part of a general physical exam and is performed routinely in younger women so that their medical record includes a baseline ECG. It gives doctors an individual patient’s “normal” ECG, which can be used later in life when looking for ECG changes that might be indicative of CHD.
Women at high risk — as well as some at intermediate risk for CHD — usually will undergo additional testing. One of the most widely used noninvasive tests for CHD is the ECG “stress test” using either exercise or a drug that stresses the heart instead of exercise. The treadmill stress test is often seen in television and film: an individual has various wires (called leads) lightly glued on the chest area. The heart’s electrical activity is then monitored during treadmill exercise.
However, for women, this particular test has “lower sensitivity” (the proportion of persons correctly identified to have a particular disease) and lower “specificity” (the proportion of persons correctly identified to NOT have a particular disease) than other types of noninvasive tests. There are ways to improve the accuracy of treadmill testing in women and your doctor will likely use these measures should you need this particular test. One is a weighted index known as the Duke Treadmill Score that combines ST segment deviation (depression or elevation of the ST wave on an ECG), treadmill time, and exercise-induced angina. A low Duke score is actually better at excluding ischemic CHD in women than men
For intermediate- or high-risk women with symptoms, their “stress test” may include some form of imaging test. A radioactive tracer may be used (then it is called a “nuclear stress test”) or an imaging technology known as ultrasound provides more insight into how the coronary arteries are responding to stress (whether exercise or pharmaceutical stress).
Catheterization
Noninvasive testing only measures regional variations in blood flow. In order to more accurately assess absolute blood flow, a woman with abnormal or reduced heart function may undergo invasive testing — called cardiac catheterization — that gives a much more detailed close-up look at the heart. A thin, flexible tube (a catheter) is carefully threaded through blood vessels to the heart. If intervention is necessary to fix a problem that is detected at this point, such as percutaneous coronary intervention (PCI) or stenting, it is often done at the same time, thus avoiding repeat catheterization.
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Treatment
Because CHD can be any one of a variety of heart conditions, there is no single one treatment for it. The greater concern for women is whether or not they will receive appropriate treatment for their cardiac condition. One way to ensure better care is to get to a hospital quickly if the problem is acute or urgent. Studies have shown that women with chest pain wait too long to go to the emergency room, delaying the time they will receive antithrombotic drugs that will help break up clots. These drugs have been shown to be 50% effective if delivered within the first hour following an MI, but only 20% if given within 2 to 6 hours of the attack.
Guidelines provide a great deal of information as to specific treatments for different diseases of the heart. Some involve medical therapy while others require surgical intervention. One of the more widely used interventions to clear blocked arteries is percutaneous coronary intervention (PCI), which often also is known as angioplasty. In these procedures, a small catheter is threaded to the blocked area and the artery is opened with via an inflated balloon or a metal cage called a stent that is placed in the artery.
Success rates with PCI were once considered suspect in women as compared to men, and women received PCIs had a lower rate than men; in fact, only about 33% of PCIs are performed in women. However, this was likely due to early studies that suggested women had higher death and complication rates with PCIs. A more recent review of the literature found that PCIs are safe and effective in women as well as men and that outcomes have been improving, especially with the addition of drugs to the stents to help ward off new plaque forming in the formerly blocked areas of the arteries. (These are called drug-eluting stents and are now used in the majority of stent procedures performed).
The bottom line with treatment — surgical or medical — is that women need to be diagnosed promptly and referred for treatment earlier than they have tended to be referred in the past.
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Prevention
Once women place the same importance on preventing and detecting CHD as they do on their annual mammogram, we will be a much healthier nation. It will also improve the health of every member of her family. Women make 70% of their family’s health care decisions and are role models for their children, and often, their spouses. When women make heart healthy lifestyle choices, their families often do too.
Choosing a healthier lifestyle — a heart healthy diet, increasing physical activity, maintaining a healthy weight, no smoking, and alcohol in moderation — will go a long way towards preventing CHD in women and, for women who already have CHD, reduce the risk of heart attack, stroke, and death from CHD.
What about aspirin?
A well publicized means of reducing CHD risk in men is daily low-dose aspirin. Aspirin, already considered a “wonder drug” by many, gained even more supporters as a result of five primary prevention trials involving more than 55,000 participants. (Primary prevention refers to efforts to stop a disease from occurring or prevent its first manifestation — such as a heart attack — while secondary prevention refers to preventing an event or a recurrent event once a disease has been diagnosed.) The results from these trials showed that the risk of having a heart attack dropped 32% with daily aspirin, with no effect on first stroke. However, in three of these trials, only men were studied. Additionally, of the 2,402 vascular endpoints seen in the five trials, less than 180 occurred in women.
Investigators subsequently convened the Women’s Health Study to determine the lowest dose of aspirin that is cardioprotective in women. Nearly 40,000 women participated in the trial, and they were followed for a mean of 10.1 years.
Surprisingly, aspirin’s ability to prevent heart attack in women was quite different than that previously reported in men. Compared to placebo, aspirin did not significantly reduce the risk of having a heart attack, however did reduce first stroke by 20%. Aspirin did provide a more consistent benefit in older women (those 65 years or older); this group of women was the only one in whom aspirin significantly reduced the risk of a heart attack.
Why the big difference between men and women? These gender differences may be related to the way men and women accumulate plaque in small (stroke) and larger (heart attack) arteries or how they metabolize aspirin. Overall, a woman should not assume aspirin will help ward off a first heart attack, nor should a man assume it will prevent against first stroke — consult with your doctor to determine if a low-dose aspirin a day really will help prevent cardiovascular events. It is important to remember that difference is relevant for primary prevention only; women and men who have suffered prior heart attacks and/or strokes get equal benefit from low dose aspirin to prevent recurrent attacks.
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Living With CHD
If you are diagnosed with CHD, you will need to discuss all lifestyle changes necessary to reduce or limit your risk. Your cardiologist will undoubtedly recommend lifestyle changes to get your weight within a healthy range, ensure that your cholesterol and other lipids are at protective levels, optimize your blood pressure, and deal with your blood glucose to prevent diabetes or make sure your diabetes is well controlled.
In many instances, you will be prescribed medications to help control these risk factors, such as statins for lipids or diuretics for blood pressure. In other cases, your doctor may reduce medications you take for other conditions to ensure that that they do not interact with those for your heart.
“The pill” and CHD
One area that remains controversial is the use of birth control by women with diagnosed CHD. One small study noted that use of oral contraceptives by young women increased the level of C-reactive protein, a marker of inflammation that is linked to CHD. Another study of 1,300 women between the ages of 33 and 55 found that long-term use of the pill raised the rate of plaque build-up in the arteries by 20% to 30% for every decade of use, although a newer study suggests it prevents plaque buildup later in the menopause. More research is needed.
One important point: some of the studies that raised concerns used earlier forms of “the pill.” Studies of second- and third-generation oral contraceptives, the ones in general use today, showed no increased risk for heart attack. Also, there is evidence suggesting that while postmenopausal hormone replacement therapy may not be cardioprotective, it may not be harmful either.
Thus, if you are taking oral contraceptives at any age, talk to your doctor about the pros and cons and make sure you understand your risk of developing CHD.
Cardiac rehabilitation
Cardiac rehabilitation – or cardiac rehab for short – is extremely beneficial but vastly underutilized. In late 2007, the American College of Cardiology, joined by several other medical societies, initiated a new strategy to expand the use of cardiac rehab. These programs improve the health and life expectancy of people who have had a heart attack, heart bypass surgery, heart valve surgery, or angioplasty or stenting to open one or more blocked arteries. Even someone who has developed chest pain caused by narrowed coronary arteries (known as angina) can enroll in a cardiac rehab program.
What’s the benefit? For example, they reduce the risk of death after a cardiac event 20-25% — that’s a level of benefit similar to that of statin drugs, beta blockers, and aspirin! They can also boost physical strength and endurance by 20-50%, an improvement that could determine whether someone is able to return to an active life.
Cardiac rehab is not just medically-supervised exercise; it helps everyone in different ways. It is also a coordinated program that assesses each person’s clinical condition and risk factors, provides education and support for living a healthier life, and works to prevent repeated episodes of cardiac illness, such as a second heart attack. Without cardiac rehab, patients don’t know what they can and can’t do, so they may sit on the couch and watch TV. They may not get any help to stop smoking, so they continue to smoke. They may not get any help to lose weight, so they gain even more weight.
Unfortunately, fewer than 30% of eligible patients participate in a cardiac rehab program. One goal of the new program to expand the use of cardiac rehab is to make referral to such programs as automatic as giving aspirin during a heart attack. The program encourages healthcare providers, healthcare systems and health insurance carriers to work together to help all eligible patients participate in such programs.
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Guidelines and Other Resources
Mosca L, Banka CL, Benjamin EJ, et al. Evidence-based guidelines for cardiovascular disease prevention in women: 2007 update. Circulation 2007;115:1481-501.
Mieres JH, Shaw LJ, Arai A, et al.. Role of noninvasive testing in the clinical evaluation of women with suspected coronary artery disease: Consensus statement from the Cardiac Imaging Committee, Council on Clinical Cardiology, and the Cardiovascular Imaging and Intervention Committee, Council on Cardiovascular Radiology and Intervention, American Heart Association. Circulation 2005;111:682-96.
Lansky AJ, Hochman JS, Ward PA, et al. Percutaneous coronary intervention and adjunctive pharmacotherapy in women: a statement for healthcare professionals from the American Heart Association. Circulation. 2005;111:940-53.
WomensHealth.gov
The Federal Government Source for Womens Health Information
http://www.4woman.gov/faq/heart-disease.cfm
Centers for Disease Control and Prevention: CHD:
http://www.cdc.gov/heartdisease/index.htm
Women’s Health Initiative:
http://www.nhlbi.nih.gov/whi/index.html
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References
Christian AH, Rosamond W, White AR, Mosca L. Nine-year trends and racial and ethnic disparities in women's awareness of CHD and stroke: an American Heart Association national study. J Womens Health (Larchmt). 2007;16:68-81.
Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable angina—summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). J Am Coll Cardiol 2003;41:159-68.
Heiss G, Wallace R, Garnet L. Anderson GL, et al. Health risks and benefits 3 years after stopping randomized treatment with estrogen and progestin.
J
AMA
2008;299(9):1036-45.
Lloyd-Jones D, Adams R, Carnethon M, et al. CHD and stroke statistics — 2009 update. A report from the American Heart Association statistics committee and stroke statistics subcommittee. Circulation 2009;119:e1-e161.
Ridker PM, Cook NR, Lee IM, et al. A randomized trial of low-dose aspirin in the primary prevention of cardiovascular disease in women.
N Engl J Med 2005;352:1293-304.
Shaw LJ, Bairey Merz CN, Pepine CJ, et al. Insights From the NHLBI-Sponsored Women’s Ischemia Syndrome Evaluation (WISE) Study: Part I: Gender Differences in Traditional and Novel Risk Factors, Symptom Evaluation, and Gender-Optimized Diagnostic Strategies. J Am Coll Cardiol 2006;47:S4-S20.
Tobin JN, Wassertheil-Smoller S, Wexler JP, et al. Sex bias in considering coronary bypass surgery. Ann Intern Med 1987;107:19-25.
Wizemann TM, Pardue M-L, editors. Exploring the biological contributions to human health. Does sex matter? Institute of Medicine: Washington, DC; 2001.
Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. Principal results from the Women's Health Initiative randomized controlled trial.
JAMA 2002;288:321-333.
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