Update on Heart Disease in Women
While most women live in fear of breast cancer, many are still unaware that
they are more likely to die from heart disease. A 1995
Gallup survey showed that four out of five women and one out of three of
their primary care doctors did not know that heart disease was the number one
cause of death for American women. With increasing publicity and attention by
the media and the medical profession, awareness of coronary heart disease (CHD)
in women is improving. The Women’s Heart Institute at Cardiovascular Medical
Group of Southern California (CVMG) is proud to play a role in raising awareness
and helping to fight heart disease in women.
What are some of the differences in CHD in women?
Women tend to develop their heart disease symptoms about 10 years later in life than men do. Most researchers feel that women are protected from CHD because they have better lipid levels and blood vessel function while they still have female hormones. A postmenopausal woman is 3 times more likely to suffer from CHD than a premenopausal woman is.
According to dozens of published studies, women with a heart attack go to the hospital up to one hour later than men do. In the past, they often took more time to be diagnosed in the emergency room, however, recent programs have effectively improved treatment once women reach the emergency room. Women still receive less aggressive treatment, including the clot-busting thrombolysis, but if a woman is treated aggressively in the emergency room, she continues during her hospitalization to get current treatment recommendations. However, disparities continue to persist with the outpatient diagnosis and treatment of women.
Women with known CHD are prescribed recommended treatments to prevent recurrent heart attacks less often than men are. And even when they are prescribed the medications, women use less aspirin, less beta blockers and less lipid lowering medications after a first heart attack than men do.
Total and LDL cholesterol levels do not predict CHD in women as well as it does in men. HDL cholesterol is a better predictor in women than in men. Yet, treatment of LDL cholesterol with diet, exercise and medications reduces a woman’s likelihood of developing CHD, even more than it does in men! The fact is that women who already have CHD and are at greatest risk of future cardiac events do not reach their target LDL level of < 100 mg/dL. A major study showed that only 10% of women with CHD reach this target LDL level.
Women with CHD complain less often of the typical cardiac symptoms in their mid and left chest and arm than men do. Women tend to have more back, right chest, abdominal and throat symptoms as their angina or heart pains. Women also have more shortness of breath, nausea or weakness as their only cardiac complaint.
The standard treadmill test used to screen or evaluate for CHD is notoriously inaccurate in women, showing EKG changes that suggest coronary blockages in 40% of premenopausal cases and up to 60% of postmenopausal cases where the woman does NOT have a problem (a false positive test). This compares to a false positive rate of up to 10% in men. We recommend that ANY treadmill test that suggests significant CHD be followed up with a more sensitive diagnostic imaging test, such as a nuclear perfusion stress test or stress echo. Otherwise, women with CHD will not be definitively identified and treated appropriately, while women without CHD may be subjected needlessly to invasive tests and treatments. Many women will prefer to do these more gender-sensitive diagnostic tests first.
The Coronary Calcium Screening Test (also known as the Electron Beam CT or rapid CT of the coronary arteries) is less accurate in women, especially younger women, than in men. Women calcify their coronary arteries at a slower rate than men do so a woman may have more noncalcified plaque and have a low score, giving a false sense of security with this test. When elevated scores are found in women, they mean that the blood vessels have had plaque present for several years. This is a signal that aggressive cardiac risk factor treatment should be undertaken. While all possible cardiac symptoms should be evaluated, a woman with possible cardiac symptoms and a positive coronary calcium score should be carefully evaluated for obstructive coronary disease with gender sensitive testing.
What risk factors have a greater impact on a woman’s risk for CHD?
Diabetes increases a woman’s likelihood of CHD tremendously by 3 to 7 times. A diabetic woman has twice the risk of CHD as a diabetic man.
A woman who smokes gets her first heart attack 19 years earlier than a nonsmoker. Stopping smoking is the single most effective thing you can do to prevent heart disease or reduce its recurrence.
Overweight women have an 80-percent increased risk of heart disease compared to lean women. A diet low in cholesterol and saturated fat and high in fruits, vegetables and complex carbohydrates is recommended for all. Calorie intake should be balanced with physical activity to reduce the many risk factors affected by excess weight.
Hypertension is especially critical for African-American women, who have double the risk of death from CHD compared with other ethnic groups. You can help lower high blood pressure yourself through weight reduction, exercise, salt restriction, and a diet high in fruits, vegetables and low-fat dairy products. Having your blood pressure checked regularly and taking your prescribed medications helps reduce the likelihood of heart attack, stroke, kidney and congestive heart failure and may reduce complications from other diseases such as diabetes.
Estrogen has a beneficial effect on lipids and blood vessel function and maintains normal blood vessel responses to stress, even in the face of blood vessel damage. Healthy blood vessel function may not be able to be restored after years of estrogen deficiency, but appears, in laboratory studies, to be able to be maintained with continued use. Estrogen may also interact with blood clotting mutations to increase blood clots and acute cardiac events in certain women. Population studies have shown a benefit for women in preventing the development of CHD (by up to 50%) and in reducing recurrent events if a woman has CHD (by 70% or more.) However, a recent studies giving estrogen to women that have NOT been on estrogen for many years had significant adverse events, such as heart attack and stroke, and has raised questions about the safety of starting full dosages of hormone replacement in women who have been estrogen deficit for some time. We have NO randomized data on the safety of hormone therapy in women who have been continued on estrogen through menopause and have normal blood clotting studies. Women should discuss their cardiac risks and hormonal options BEFORE menopause if possible so that a clear and appropriate decision on hormone replacement can be made when the time comes. Postmenopausal women, especially women at high risk or who already have CHD, need to have this discussion with knowledgeable experts so that current recommendations and unknowns are taken into account.
What new research applies to women?
The Heart and Estrogen/progestin Replacement Study (HERS) (1998) looked at cardiac events occurring in post-menopausal women with established CHD who were started on full doses of hormone replacement therapy (HRT) of conjugated estrogen and artificial progesterone. The study found no overall benefit for HRT over 5 years (and 6+ years on follow up) compared to placebo. However, the results of this study were most telling when looked at over time. There was a significant increase in cardiac events in the first year of treatment, with fewer events after the third year of therapy compared to placebo. There was no substantial benefit averaged over 5 and 6+ years but a definite trend for benefit was seen in the later years of the study. We don't understand why there was an early adverse effect of full dosages of HRT in women with established CHD. Some researchers believe it may be related to increased clotting in women with clotting mutations or other instability found in women with CHD that is aggravated by full dosages of HRT. This adverse effect would be offset with time by a beneficial effect of HRT with continued use. We don't know what the effect will be of starting and maintaining estrogen in women at the time of perimenopausal symptoms, other formulations of HRT (such as progesterone rather than a progestin or other formulations of estrogen) or starting with lower dosages of therapy. For women with established CHD already on HRT for at least one year, it seems reasonable to continue therapy is a woman desires it for other symptoms or concerns. However, HERS points out that there is a danger to starting full dosages of HRT in women with established CHD and it can not be recommended at this time. Interestingly, in the women in HERS on statins, their risk of blood clots and cardiac events was dramatically reduced. HERS also did not find any increased risk of breast cancer on HRT. The HERS data do not apply to women without established CHD who are considering HRT or to women on other hormone regimens or who were on estrogen continuously since menopause. This issue points out the importance of a full discussion of HRT, its risk, benefits and alternatives, before the need arises. In this way, all risk factors and considerations can be taken into account and women can fully understand and participate in this decision process.The Women's Health Initiative (WHI) (2002) looked at presumably healthy postmenopausal women from age 50 to 79 and enrolled them on HRT consisting of conjugated estrogen and progestin or placebo. This study was prematurely stopped because of an increased risk of breast cancer that almost reached statistical significance. The breast cancer increased risk of concern was only found in women who had been on some hormones before the study, though those regimens were not detailed, and was not found in the 75% of women who had not been on hormones before the study. A higher risk of cardiac events, strokes and blood clots were found in the women on HRT, while lower risks of fractures, bowel cancer and slightly lower risk of overall death. were noted in the women on HRT. Of all these risks, only the risk of blood clots in the legs and to the lungs reached statistical significance.
While there are a significant number of confounding issues i WHI similar to HERS (in WHI, three-quarters of the women had never been on hormones so participants were enrolled up to 30 years after menopause and results were not given with respect to blood clotting mutations) this study has been interpreted by the authors and most media as saying that this hormone regimen should not be given to women. Of interest, the major reason for postmenopausal hormone therapy, for symptoms of menopause, was not evaluated or taken into account in these studies. For a detailed critical evaluation of these hormonal studies, please see hormones and the heart..
Fortunately, a number of studies were reported in the past few years which included enough women to give us the information we need. about therapies that have proven benefit. These include studies showing that low dose aspirin reduces cardiac events in women with risk factors for heart disease. Three studies show the benefit of lowering LDL cholesterol levels in women, two showing the results of secondary prevention (in patients with established CHD) and one showing the results of primary prevention (in patients without evidence of CHD). The Scandinavian Simvastatin Survival Study (4S) study (1994) showed that women and older patients with established CHD and elevated LDL benefit even more than men do in reducing future cardiac events (risk reduction 35%) and cardiac deaths (risk reduction of 43% compared to placebo). The Cholesterol and Recurrent Events (CARE) study (1996) showed that women with established CHD and normal LDL benefit with reduced cardiac risk across the full range of cholesterol levels (46% reduction in coronary events) more than men (20% reduction). The Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAP/TexCAPS) (1998) showed that women without CHD with average LDL and low to normal HDL levels benefit even more than men did. This study was important in that it showed reduction in first cardiac events with treatment of average LDL and low to normal HDL levels in patients without CHD, with an even greater benefit in women than in men (46% risk reduction in women versus 37% in men). In spite of these strong statistics, recent study data show that less than 10% of women reach the recommended target of an LDL < 100 mg/dL within one year of their heart attack.
| 4S | CARE | AFCAP/ TexCAPS |
|
| Cardiac Risk reduction compared to placebo | 35% | 46% | 46% |
| Risk reduction for women compared to men | yes | 20% | 37% |
Where can doctors and the public find out about the latest recommendations on CHD in women?
The American Heart Association and the American College of Cardiology published their Scientific Consensus Panel Statement to help physicians and the public understand the impact of the differences in CHD in women and apply the latest information available. Their "Guide to Preventive Cardiology for Women" by Lori Mosca, Scott Grundy, Debra Judelson, et al (Circulation. 1999;99:2480-2484, published May 11, 1999) reviews many of the issues discussed above and sets goals, screening guidelines and recommendations for lifestyle risk factors, diabetes, lipids and pharmacologic interventions.
Cardiovascular Medical Group is proud of Dr. Judelson’s role in helping to establish the standard of care in coronary heart disease for all women. Our Women’s Heart Institute will continue its efforts to educate physicians and the public about these advances.
Last updated on October 17, 2002 .