Cardiovascular disease is the most common cause of death in the United States and, as a category, includes coronary heart disease (CHD), cerebro-vascular disease (stroke), hypertension and peripheral vascular disease. The underlying pathologic condition in most cases of coronary heart disease, peripheral vascular disease and stroke is atherosclerosis. The formation of atherosclerotic placques is a complex process involving smooth muscle cell proliferation and lipid deposition that eventually narrows the involved arteries. When the narrowing of vessels compromises blood supply, end-organ damage may result, e.g., heart attack or stroke.
Although the exact mechanisms of atherogenesis have not been fully elucidated, risk factors for the development of cardiovascular disease have been identified. Clearly identified risk factors include high blood cholesterol, high blood pressure, cigarette smoking, diabetes, a family history of atherosclerosis, advancing age, male sex and obesity. Control of factors can lead to decreased cardiovascular mortality. A 1972-79 Hypertension Detection and Follow-up Program (HDFP) demonstrated a 17% decline in overall mortality, a 45% decline in stroke mortality and a 26% reduction in the heart attack death rate among hypertensive patients through a vigorous goal-focused program, compared to hypertensives receiving routine care in the community. Numerous studies have demonstrated that smokers have a risk of cardiopulmonary mortality 1.6 times greater than nonsmokers.
From 1964-1984, coronary heart disease mortality declined 40% and stroke mortality declined 55%. This improvement may be attributed to numerous efforts to reduce cardiovascular disease risk factors. The percentage of males (20 years and older) who smoke cigarettes decreased from 52.1% in 1965 to 32% in 1985, while the decrease among females was from 34.2% in 1965 to 28% in 1983. The percentage of persons 25 to 74 years of age with high-risk cholesterol levels has decreased from 26.9% in 1960-62 to 21.9% in 1976-80. From 1960-1980 the percentage of persons with blood pressure higher or equal to 160/95 remained at 21%, the percentage of those with blood pressure higher or equal to 140/90 remained at 41% and the proportion of overweight persons remained at about 28% in the US; but public awareness of the importance of high blood pressure screening and control increased significantly, leading to increases in the number of persons with hypertension receiving treatment to control their condition. If the decline in cardiovascular disease mortality is to continue, further preventive efforts are in order.
Incidence and Prevalence
All Cardiovascular Diseases
An estimated 6 million persons in the U.S. have coronary heart disease, 2 million have cerebrovascular disease and 58 million have hypertension.
The American Heart Association estimates that 63,290,000 persons in the U.S. have cardiovascular disease, many having more than one cardiovascular disorder.
From 1970-1983 death rates for diseases of the heart dropped 25.5% for all persons in the U.S.; however for Black males the decline was 18.0%, for Black females 23.9%, for white females 24.5% and for white males 25.8%.
Cardiovascular diseases result in nearly 2.5 million potential years of life lost before age 65, including 1.4 million years lost due to coronary heart disease and 0.3 million due to strokes.
Coronary Heart Disease
The American Heart Association estimates that in 1986 as many as 1,500,000 Americans will have heart attacks resulting in 550,000 deaths.
There are about 4,000 heart attacks each day in the United States, or nearly 3 heart attacks every minute.
2.7% of the U.S. population or 6,033,000 persons reported having ischemic heart disease during the 1982 National Health Interview Survey.
The American Heart Association estimates that 4,740,000 Americans alive today have a history of heart attack, angina pectoris or both.
The chance of an American male developing coronary artery disease before age 60 is one in five.
Sudden death is the presenting symptom in 1 out of 5 coronary attacks.
20% of myocardial infarctions are unrecognized, with half of those being silent and half being so atypical that they are unrecognized by the patient and physician.
Within 5 years of an initial infarction, 13% of men and almost 40% of women develop a second infarction.
While the case-fatality rate is 30% for initial infarctions and 50% for recurrences, the 10-year survival rate is 50% for men and 30% for women.
About 80% of coronary mortality in persons under age 65 occurs during the initial coronary attack.
20% of men and 45% of women die in the first year following a myocardial infarction.
766,130 persons died in the U.S. in 1984 as a result of disease of the heart. 540,380 of these deaths (70.5%) were due to ischemic heart disease including 279,810 acute myocardial infarctions.
About 500,000 persons suffer strokes each year in the United States. The chance of having a stroke before age 70 is 1 in 20 for either sex.
The incidence of stroke rises from 1 per 1,000 per year at ages 45 to 54 to 9 per 1,000 per year at ages 65 to 74.
There are about 1.9 million stroke patients in the U.S., for a prevalence of 8 stroke patients per 1,000 population.
The prevalence of cerebrovascular disease rises from 2 per 1,000 adults under age 45, to 13 per 1,000 ages 45 to 64 and to 45 per 1,000 over age 65.
In 1984, cerebrovascular disease was the third leading cause of death in the U.S. behind heart disease and cancer. In 1984, 155,010 deaths from cerebrovascular diseases were recorded according to provisional figures from the National Center for Health Statistics.
86% of stroke deaths occur in persons over age 65.
Cerebrovascular disease death rates for each race/sex group declined 48% from 1970 to 1983.
The 1983 cerebrovascular disease death rates for Black males and Black females are both 1.8 times the rates for white males and females.
Other Cardiovascular Diseases
Cardiac Failure. Cardiac failure is a consequence of a variety of heart diseases. Coronary heart disease is responsible for 39% of cardiac failure cases, rheumatic heart disease is responsible for 21% of cases and hypertension is involved in 75% of cases.
Over 2 million Americans have heart failure, with at least 250,000 new cases occurring each year, requiring 500,000 to 1,000,000 hospitalizations annually.
Rheumatic Heart Disease. Rheumatic heart disease affects 100,000 children and 1,980,000 adults in the U.S., according to estimates of the American Heart Association.
Annual mortality from rheumatic heart disease has declined to 6,880 deaths in 1984, reflecting an 85% decline in the age-adjusted death rate from 1950-1982.
Congenital Heart Disease. An estimated 25,000 infants are born with congenital heart defects per year in the U.S., or about 7 per 1,000 births.
About 6,400 deaths from congenital heart disease occur each year in the U.S., or about 2 deaths per 1,000 live births.
Risk Factor Prevalence
Demographic Risk Factors
Age/Sex. The incidence of all cardiovascular diseases increases with age and is higher among males than females:
According to the Framingham Heart Study, 5% of all heart attacks occur in individuals under age 40, and 45% occur in individuals under age 65.
In 1983 the age-adjusted death rates for diseases of the heart among all males (260.4 per 100,000) was twice the rate for all females (132.3 per 100,000).
Race. Blacks are 1.3 times more likely than whites to have blood pressures of 140/90 or above, and 1.4 times more likely than whites to have blood pressures of 160/95 or above.
The age-adjusted death rate for all cardiovascular diseases among Blacks (315.4 deaths per 100,000) in 1983 was 1.4 times that of whites (228.1).
The 1983 age-adjusted cerebrovascular disease death rate for Blacks was 1.8 times that of whites.
Geographic Distribution. In 1980, stroke mortality rates in the South were 12.5% higher than in all other regions of the country. The increased stroke mortality in the South was most apparent among Blacks. The stroke mortality rate among Black males in the South was 42.4% higher than the rate for Black males in all other regions. For Black females the difference was 15.7%, for white males 1.5% and for white females 7.6%.
The prevalence of high blood pressure (BP higher or equal to 140/90 or on hypertension medication) is higher in the South (31%) than all other regions (29%). Among males and white females, there was little or no regional variation in high blood pressure prevalence, but among Black females 44% of those in the South compared to 34% of those in all other regions had high blood pressure.
Fewer Black female hypertensives in the South (32.9%) control their high blood pressure at 160/95 than do Black female hypertensives in all other regions (46.2%).
Black hypertensives in the South are 2.6 times as likely as Black hypertensives elsewhere to have severly elevated diastolic pressures (higher than 115 mmHg).
Obesity is more common among Black hypertensives in the South (about 71%) than Black hypertensives in all other regions (about 53%).
In 1985, about 32% of adult males were smokers, a slight decrease from 1980. From 1980-1985 the percentage of adult women (over age 18) who smoked cigarettes decreased from 30%-28% though an increase occurred among women under 24 years of age.
A Carter Center report estimated that in 1980 14% of coronary heart disease deaths, or about 78,000 deaths per year were attributable to smoking.
About 11% (or 240,000 cases) of stroke could be prevented if smoking were eliminated, according to the Carter Center report.
Smoking is believed responsible for a total of 145,319 cardiovascular deaths in 1980.
Serum cholesterol levels were found to be elevated among about 20% of males and about 35% of females ages 55-74 years in the 1976-80 NHANES II.
10% of the nearly 1 million cardiovascular disease deaths that occur each year have been attributed to serum cholesterol greater than 219 mg/dl, but other estimates that the total contribution of dietary fat is about 30%.
The prevalence of obesity among persons 35-74 years in the U.S. was 29% of white males, 35% of Black males, 31% of white females and 55% of Black females, according to the 1976-80 NHANES II. (Obesity was defined as body mass greater than the sex-specific 85th percentiles for 20-29 year olds.)
[Hypertension is the most prevalent cardiovascular disease and an important contributor to coronary heart disease and cerebrovascular disease morbidity and mortality. Unless otherwise noted, hypertension is defined as blood pressure greater than 140/90 mmHg or controlled below that level by hypertension medication.]
58 million Americans have high blood pressure (BP higher or equal to 140/90) or take anti-high blood pressure medication. Those whose high blood pressure is not controlled are at increased risk of morbidity and premature mortality associated with high blood pressure.
Data from the 1976-80 National Health and Nutrition Examination Survey (NHANES II) using 140/90 as the criteria for elevated blood pressure showed that among persons 18-74 years of age 33% of men and 26.8% of women had high blood pressure. The NHANES II data revealed that 38.2% of Blacks and 28.8% of whites had high blood pressure.
Approximately one-half of those suffering a first heart attack and two-thirds of those suffering a first stroke have blood pressures 160/95 mmHg or above.
Provisional 1984 figures show 30,570 deaths due to hypertension as the underlying cause. In addition hypertension is the main contributor to the 155,010 deaths from stroke as well as many of the 540,380 deaths from coronary heart disease and 20,050 deaths from kidney disease. It is estimated that hypertension contributes to a total of 250,000 deaths per year in the U.S.
Mortality attributed to hypertension has declined an estimated 7% per year in the 1970s as a result of earlier detection and more vigorous treatment. The decline in hypertension mortality has contributed to the 5% per year decline in stroke mortality since 1970.
Hypertension may cause 30% of all cardiovascular deaths including 29% of coronary heart disease (CHD) deaths and 32% of stroke deaths, according to a Carter Center report.
The number of cardiovascular disease deaths that could be prevented each year if high blood pressure were eliminated is estimated at 292,504, including 164,837 coronary heart disease (CHD) deaths and 54,642 stroke deaths.
Health Care Services
About two-thirds of myocardial infarction patients do not make a complete recovery, but 88% under the age of 65 are able to return to their usual occupations.
Of the nearly 2 million stroke patients in the U.S., 40% require special services and 10% total care.
In the Framingham Study, 31% of stroke survivors needed assistance in self care, 20% required help in ambulation and 71% had an impaired vocational capacity when examined an average of 7 years after their stroke.
In 1984, 2,101,000 operations on the cardiovascular system were performed, including 314,000 open heart surgeries (202,000 heart revascularizations), 570,000 cardiac catheterizations and 208,000 procedures involving pacemakers.
Of the 202,000 coronary artery bypass surgeries performed in 1984 in the U.S., 156,000 (77%) of the patients were male and 46,000 (23%) were female.
The number and rate of coronary artery bypass operations in the U.S. increased more than 12 fold from 14,000 operations and a rate of 6.9 per 100,000 population in 1970 to 202,000 and a rate of 86.3 per 100,000 in 1984.
In 1984, 5,593,000 patients were discharged from U.S. hospitals with diseases of circulatory system including 3,599,000 with heart disease, 896,000 with cerebrovascular disease and 266,000 with hypertension.
Of the 3,599,000 discharges for heart disease in 1984, 700,000 were listed as acute myocardial infarctions and 531,000 as congestive heart failure.
The average length of hospital stay for those with cerebrovascular disease in 1984 was 10.4 days; for those who had heart attacks, 10.0 days and for those with congestive heart failure, 8.6 days.
In 1983, heart disease accounted for more total days of hospital care (30,781,000) than any other diagnosis including deliveries or cancer.
The economic cost of cardiovascular disease in 1983 in the U.S. was an estimated $102 billion, including $48 billion in direct health expenditures, $13 billion in indirect cost of morbidity and $41 billion in indirect cost of mortality.
The American Heart Association estimates the 1986 economic costs of cardiovascular diseases to be $11.8 billion for physician and nursing services, $48.2 billion for hospital and nursing home services, $5.0 billion for medication and $13.6 billion for lost output due to disability, for a total cost of $78.6 billion.
A national survey of office-based physicians in 1981 revealed that 10.6% of all drug mentions were for cardiovascular drugs.
Cardiovascular drugs accounted for 14% of drugstore pharmaceutical costs in 1982, resulting in $1,495,800,000 in drug-store expenditures, more than any other therapeutic class of medications.
Total drugstore and hospital expenditures on cardiovascular drugs reached $1,728,500,000 in 1982.