Coronary heart disease (CHD), also known as atherosclerosis, coronary artery disease, and ischemic heart disease is caused by a blockage in the coronary arteries that supply blood to the heart. This blockage results from the narrowing of the arteries by a gradual build up of cholesterol deposits on the inner portion of the walls lining the coronary arteries. These deposits or plaques harden and clog the lumen of the arteries over a period similar to the salt deposits that reduce the water flow in the water supply lines.
According to Heart Disease and Stroke Statistics released by the American Heart Association, the National Heart Lung and Blood Institute, and the U.S. Department of Health and Human Services, CHD is the most common type of heart disease in the United States as well as the primary cause of death for both men and women. The data shows that 16.3 million Americans above the age of twenty years have CHD irrespective of gender and race. Data also shows CHD as the cause of more than fifty percent of all cardiovascular diseases in both men and women.
While there is no structural or functional difference in the hearts of men and women, there is actually a marked gender difference in mortality and disease prevalence. According to the National Health and Nutrition Examination Survey on the prevalence of CHD in the US, of the total 16,300 cases of CHD identified, 8, 800 were men and 7, 500 women. Further, there are also distinct gender differences in the clinical presentation of heart diseases, which poses a challenge for prompt diagnosis. Published data since 2008 shows a higher mortality and hospitalization in men than women. The documented mortality rate in men was 8.3% as compared to 6.1 % in women in USA in 2008. A lower mortality in women does not mean that women are less prone to CHDs.
The statement for Healthcare Professionals from the American Heart Association on cardiovascular diseases in women has listed cigarette smoking, hypertension (especially isolated systolic hypertension), dyslipidemia, diabetes mellitus, obesity, sedentary lifestyle, and poor nutrition as the major risk factors for coronary heart diseases (CHD) in women. It is critical to note that women typically experience cardiovascular symptoms that do not include chest pain. Typical symptoms in women include a sudden onset of discomfort in neck, shoulder, upper back or abdomen, shortness of breath, nausea or vomiting, profuse sweating, lightheadedness or dizziness, and unusual fatigue in contrast to the more prominent, crushing chest pain experienced during cardiovascular events in men.
Age plays an important role in the prevalence of CHD. According to the survey data provided by the National Health and Nutrition Examination Survey 2005-2008, both men and women become more prone to CHD risk with advancing age. The risk of CHD is high in men between 45 and 64 years. In women, the risk is high after 74 years. Both men and women are at CHD risk beyond 70 years. The risk is moderate between 35 and 45 years in both men and women. The risk is low below 30 years in both men and women. Overall prevalence is greatly influenced by the aforementioned risk factors.
Racial differences in the prevalence of CHD have been well documented by epidemiological studies. The racial difference in the disease prevalence is an evolutionary trend and is governed by genetic factors, rather than sociological factors. Statistical data available from the state of New Hampshire shows that white males are more prone to CHD when compared to African American, Mexican American, Hispanic or Latino, Asian and Alaskan natives. The prevalence rate among the population above 20 years of age is 8.5 % for whites, 7.9 % for African Americans, 6.3% for Mexican Americans, 5.2% for Hispanics, and 4.9% for Asians. The mortality rate is the highest among whites.
High blood cholesterol levels, hypertension, insulin resistance, diabetes, obesity, sedentary life style, high fat diet, low dietary fiber intake, smoking, alcohol consumption, and age are known risk factors for CHD prevalence. According to National Health and Nutrition Examination Survey 1971-2006, a systolic blood pressure >120 mm Hg and a diastolic blood pressure >80, blood cholesterol levels >200 mg/Dl, a body mass index >25 kg/m2, smoking, and diabetes are high risk factors over a period of 10 years for adults above 20 years of age.
Ongoing research is identifying additional risk factors. The presence of excess homocysteine, an amino acid, in the blood was recently deemed a risk factor for cardiovascular disease. C-reactive protein (CRP) produced in response to inflammatory conditions is another major risk factor. A high level of triglycerides and preeclampsia are potential risk factors in pregnant women. Stress and sleep apnea have been recently recognized as important risk factors for CHD. Data released by the American Heart Association shows that smoking, diabetes, high blood pressure, and high blood cholesterol as the major risk factors for those belonging to the 55-year-old group.