Heart disease affects women of all racial and ethnic groups, as well as women with other illnesses, such as diabetes.
Facts about women and cardiovascular diseases
* Cardiovascular disease (CVD) ranks first among all disease categories in hospital discharges for women.
* Over 40 percent of all female deaths in America occur from CVD, which includes coronary heart disease (CHD) and stroke.
* CVD is a particularly important problem among minority women. The death rate due to CVD is substantially higher in black women than in white women.
* In 2001, CVD claimed the lives of 498,863 females.
* In 2001, coronary heart disease claimed the lives of 248,184 females.
* 38 percent of women compared with 25 percent of men will die within one year after a heart attack.
* Stroke is a leading cause of serious, long-term disability; an estimated 15 to 30 percent of stroke survivors are permanently disabled.
* Misperceptions still exist that CVD is not a real problem for women.
* Risk of heart disease and stroke increases with age, and in the year 2001, over 43 million American women were 50 and older.
* More women than men die of stroke.
* Low blood levels of “good” cholesterol (high density lipoprotein or HDL) appears to be a stronger predictor of heart disease death in women than in men in the over 65 age group; high blood levels of triglycerides (another type of fat) may be a particularly important risk factor in women and the elderly.
* Regular physical activity and a healthy weight reduce the risk of non-insulin-dependent diabetes, which appears to be an even stronger contributing risk factor for heart disease in women than in men.
* Diagnosis of heart disease presents a greater challenge in women than in men.
* Cardiovascular disease claims more women’s lives than the next seven causes of death combined – about 500,000 women’s lives a year.
INCIDENCE
* Heart disease affects women of all racial and ethnic groups, as well as women with other illnesses, such as diabetes.
* Black women are more likely to die of heart disease than white women are
* Increasing age is also a factor in heart disease and with people age 65 and over being the fastest growing group in the U.S., heart disease is becoming a growing problem for women.
* As women age, particularly after menopause, they become more at risk for cardiovascular disease. Lower levels of estrogen during and after menopause are thought to increase a woman’s risk for cardiovascular disease. Early menopause, natural or surgical, can double a woman’s risk for developing coronary heart disease.
* Younger women are also at risk for cardiovascular disease if they smoke or have high blood pressure, diabetes, high cholesterol levels, and a family history of cardiovascular disease at young ages.
* Women with congenital heart disease (born with a heart defect) have a higher risk of having a baby with a heart defect.
* In 1994, CVD claimed the lives of more than one half million women and accounted for 45.2% of all deaths in women, more than all forms of cancer combined.
* It is estimated that 1 in 2 women will eventually die of heart disease or stroke, compared with 1 in 25 who will eventually die of breast cancer.
* Risk of death due to CHD in women is roughly similar to that of men 10 years younger.
* CHD death rates are 34% higher for black women than white women, compared with a 5% higher rate for black men compared with white men.
INCIDENCE IN INDIA
Indians are supposed as worst hit from CAD.
Study shows that
* 1:10 adult men.
* 1: 9 women (45-65 years)
* 1: 3 both men and women > 65 yrs.
Current CAD incidence in INDIA is estimated at 60 million and is expected to rise to close to 200 million in the next decade.
Risk Factors and Primary Prevention
The major risk factors for CHD in women are cigarette smoking, hypertension (including isolated systolic hypertension), dyslipidemia, diabetes mellitus, obesity, sedentary lifestyle, and poor nutrition. Although most risk factors for CHD are similar in men and women, gender differences have been documented, particularly diabetes and dyslipidemia.
Cigarette smoking remains the leading preventable cause of CHD in women, with more than 50% of MIs among middle-aged women attributable to tobacco. The magnitude of excess risk, a twofold to fourfold elevation, is similar in women and men. Risk of CHD begins to decline within months of smoking cessation and reaches the level of persons who have never smoked within 3 to 5 years. Although the prevalence of smoking among US women declined from 34% in 1965 to 24% in 1991, smoking cessation rates have declined more slowly among women than men. On the basis of current trends, it is estimated that by the year 2000 smoking rates will be higher in women (23%) than in men (20%). These changing demographics of smoking, particularly the unfavorable smoking patterns among younger women may contribute substantially to the future burden of CHD on women, as well as other smoking-related illnesses.
Epidemiological studies document a strong association between high levels of both systolic and diastolic blood pressure (BP) and risk of CHD in both women and men. Among US adults older than 45 years, 60% of white women and 79% of African-American women were classified as having hypertension. Of particular concern for older women is isolated systolic hypertension, which is estimated to affect 30% of women older than 65.
Increased total serum cholesterol and low-density lipoprotein (LDL) cholesterol are risk factors for CHD in both women and men. From 1980 to 1991 more than 50% of women older than 55 years had serum cholesterol levels that were considered high (>240 mg/dL). In a recent meta-analysis, these lipids predicted CHD mortality in women younger than 65 but not in older women. A low level of high-density lipoprotein (HDL) cholesterol, however, was a risk factor for CHD in both younger and older women and was a stronger predictor of CHD mortality in women than in men.
Obesity and sedentary lifestyle are parallel, interrelated epidemics in the United States that contribute to increased risk of CHD. The prevalence of obesity has increased among both men and women in the United States in the past decade; currently about one third of adult women (or 34 million) are classified as obese. Moreover, 60% of both men and women have no regular physical activity. Obesity, particularly abdominal adiposity, is an important risk factor for CHD in women. Although most of the epidemiological studies of exercise and CHD have been conducted in men, most studies in women suggest a comparable 50% risk reduction among active women compared with sedentary women. Recent evidence suggests that even moderate-intensity activity, including brisk walking, is associated with substantial reduction in CHD risk.
Regular exercise and maintenance of healthy weight should also help reduce insulin resistance and the risk of non–insulin-dependent diabetes mellitus, which appears to be an even stronger risk factor for CHD in women than in men. Diabetes is associated with a threefold to sevenfold elevation in CHD risk among women, compared with a twofold to threefold elevation among men, this gender-based difference may be due to a particularly deleterious effect of diabetes on lipids and blood pressure in women. Diabetes is the fourth leading cause of death among black women and third among Hispanic women aged 45 to 74 years and American-Indian women aged 65 to 74 years. It is also the second leading cause of death in Pima Indian women. Approximately half of all deaths in persons with non–insulin dependent diabetes mellitus are due to heart disease, the majority of which is ischemic heart disease.
Increasing research and knowledge related to nutrition have led to identification of several dietary factors that influence CHD risk. The epidemiological evidence is compelling: diets low in saturated fat and high in fruits, vegetables, whole grains, and fiber are associated with a reduced risk of CHD. Trans fatty acids have recently been linked to adverse lipid profiles and an increased risk of CHD. The role of other fatty acids, including monounsaturated, polyunsaturated, and marine omega-3 fatty acids, remains controversial. Moderate intake of alcohol is related to reduction of CHD but may raise blood pressure and increase risk of breast cancer.
Genetic factors are also important determinants of CHD risk in both men and women, but they are not modifiable. Recently identified thrombotic, hemostatic, and inflammatory markers for CHD have promising roles in predicting risk of vascular events, but their clinical usefulness in the general population remains largely unknown.
Diagnosis
The diagnosis of CHD presents a greater challenge in women compared with men. Gender differences in the clinical presentation of ischemic heart disease and diminished accuracy of diagnostic tools, in part due to the lower prevalence of CHD in women, may contribute to the difficulty. Elucidation of the cause of chest pain and an increased awareness of atypical symptoms of CHD in women are needed. In addition, diagnosis of unrecognized ischemia is of interest in women because of the high fatality rate associated with first MIs.
Historically, chest pain has not been perceived to be of great prognostic value in women. This is based partly on follow-up reports from the Framingham study indicating that women developed chest pain more often than men, but it rarely progressed to MI. In the same population the predictive value of angina was increased among older subsets of women.
Syndrome X, defined as exertional angina, a positive response to exercise testing and angiographically normal coronary arteries occurs predominantly in postmenopausal women.
Despite the limited prognostic value of chest pain, it remains the most common initial manifestation of CHD in women. In the Myocardial Infarction Triage and Intervention (MITI) Project, nearly 90% of women with MI had chest pain as a feature of initial clinical presentation, similar to that of men. In contrast, women with MI were significantly more likely than men to present with upper abdominal pain, dyspnea, nausea, and fatigue. Chest pain and possible atypical symptoms of angina should be pursued in women, given the appropriate clinical context and based on the underlying probability of disease.
The choice and interpretation of an array of noninvasive procedures poses unique challenges in women. Factors that influence gender differences in the accuracy of diagnostic testing include a lower prevalence of CHD and multivessel disease compared with men, sex-based differences in the pathophysiology of coronary disease and its relation to risk factors, altered referral patterns for men versus women, and features intrinsic to the testing procedure itself.
Gender-specific considerations related to diagnostic test performance might influence the choice of procedures used to evaluate chest pain syndromes in women. Electrocardiographic (ECG) stress testing in women has a lower sensitivity and specificity compared with men, not only because of gender differences in prevalence and extent of disease but also because women are less likely to achieve an adequate heart rate response and more likely to have repolarization abnormalities. In addition, hormone replacement therapy may induce a false-positive ST-segment depression, thereby reducing the specificity of ECG exercise testing in women.
Sensitivity and specificity of pharmacological or exercise treadmill testing is enhanced by added imaging techniques. Myocardial perfusion imaging with thallium 201 has improved sensitivity over conventional treadmill testing, but breast tissue attenuation of radioactivity may lead to a false-positive test result in women. Attenuation artifacts may be reduced and specificity increased with the use of newer high-energy agents such as technetium 99m Sestamibi and simultaneous ECG-gated single-photon emission computed tomography (SPECT), but data are limited in women. Radionuclide ventriculography is of limited prognostic value in women because of a reduced left ventricular response to exercise compared with men. In contrast, exercise echocardiography may be a valuable diagnostic tool in women. It is more specific than exercise electrocardiography and is considered a cost-effective approach to diagnosis of CHD in women.
These data suggest gender have a significant impact on the accuracy of widely available diagnostic tests and should be a consideration in the choice and interpretation of noninvasive tests. Emerging data on electron beam computed tomography, a noninvasive screening technique that detects coronary calcium, suggest minimal gender differences in diagnostic and prognostic usefulness.