Heart Disease and Stroke Statistics—2011 Update1. About 1. About These Statistics2. American Heart Association's 2020 Impact Goals3. Cardiovascular Diseases4. Subclinical Atherosclerosis5. Coronary Heart Disease, Acute Coronary Syndrome, and Angina Pectoris6. Stroke (Cerebrovascular Disease)7. High Blood Pressure8. Congenital Cardiovascular Defects9. Cardiomyopathy and Heart Failure10. Other Cardiovascular Diseases11. Family History and Genetics12. Risk Factor: Smoking/Tobacco Use13. Risk Factor: High Blood Cholesterol and Other Lipids14. Risk Factor: Physical Inactivity15. Risk Factor: Overweight and Obesity16. Risk Factor: Diabetes Mellitus17. End-Stage Renal Disease and Chronic Kidney Disease18. Metabolic Syndrome19. Nutrition20. Quality of Care21. Medical Procedures22. Economic Cost of Cardiovascular Disease23. At-a-Glance Summary Tables24. Glossary
A Report From the American Heart Association
We wish to thank Thomas Thom, Jonathan Pool, Michael Wolz, and Sean Coady for their valuable comments and contributions. We would like to acknowledge Karen Modesitt for her administrative assistance.
Each year, the American Heart Association (AHA), in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay public, and many others who seek the best national data available on disease morbidity and mortality and the risks, quality of care, medical procedures and operations, and costs associated with the management of these diseases in a single document. Indeed, since 1999, the Statistical Update has been cited more than 8700 times in the literature (including citations of all annual versions). In 2009 alone, the various Statistical Updates were cited ≈1600 times (data from ISI Web of Science). In recent years, the Statistical Update has undergone some major changes with the addition of new chapters and major updates across multiple areas. For this year's edition, the Statistics Committee, which produces the document for the AHA, updated all of the current chapters with the most recent nationally representative data and inclusion of relevant articles from the literature over the past year and added a new chapter detailing how family history and genetics play a role in cardiovascular disease (CVD) risk. Also, the 2011 Statistical Update is a major source for monitoring both cardiovascular health and disease in the population, with a focus on progress toward achievement of the AHA's 2020 Impact Goals. Below are a few highlights from this year's Update.
Death Rates From CVD Have Declined, Yet the Burden of Disease Remains High
The 2007 overall death rate from CVD (International Classification of Diseases 10, I00–I99) was 251.2 per 100 000. The rates were 294.0 per 100 000 for white males, 405.9 per 100 000 for black males, 205.7 per 100 000 for white females, and 286.1 per 100 000 for black females. From 1997 to 2007, the death rate from CVD declined 27.8%. Mortality data for 2007 show that CVD (I00–I99; Q20–Q28) accounted for 33.6% (813 804) of all 2 243 712 deaths in 2007, or 1 of every 2.9 deaths in the United States.
On the basis of 2007 mortality rate data, more than 2200 Americans die of CVD each day, an average of 1 death every 39 seconds. More than 150 000 Americans killed by CVD (I00–I99) in 2007 were <65 years of age. In 2007, nearly 33% of deaths due to CVD occurred before the age of 75 years, which is well before the average life expectancy of 77.9 years.
Coronary heart disease caused ≈1 of every 6 deaths in the United States in 2007. Coronary heart disease mortality in 2007 was 406 351. Each year, an estimated 785 000 Americans will have a new coronary attack, and ≈470 000 will have a recurrent attack. It is estimated that an additional 195 000 silent first myocardial infarctions occur each year. Approximately every 25 seconds, an American will have a coronary event, and approximately every minute, someone will die of one.
Each year, ≈795 000 people experience a new or recurrent stroke. Approximately 610 000 of these are first attacks, and 185 000 are recurrent attacks. Mortality data from 2007 indicate that stroke accounted for ≈1 of every 18 deaths in the United States. On average, every 40 seconds, someone in the United States has a stroke. From 1997 to 2007, the stroke death rate fell 44.8%, and the actual number of stroke deaths declined 14.7%.
In 2007, 1 in 9 death certificates (277 193 deaths) in the United States mentioned heart failure.
Prevalence and Control of Traditional Risk Factors Remains an Issue for Many Americans
Data from the National Health and Nutrition Examination Survey (NHANES) 2005–2008 indicate that 33.5% of US adults ≥20 years of age have hypertension (Table 7-1). This amounts to an estimated 76 400 000 US adults with hypertension. The prevalence of hypertension is nearly equal between men and women. African American adults have among the highest rates of hypertension in the world, at 44%. Among hypertensive adults, ≈80% are aware of their condition, 71% are using antihypertensive medication, and only 48% of those aware that they have hypertension have their condition controlled.
Despite 4 decades of progress, in 2008, among Americans ≥18 years of age, 23.1% of men and 18.3% of women continued to be cigarette smokers. In 2009, 19.5% of students in grades 9 through 12 reported current tobacco use. The percentage of the nonsmoking population with detectable serum cotinine (indicating exposure to secondhand smoke) was 46.4% in 1999 to 2004, with declines occurring, and was highest for those 4 to 11 years of age (60.5%) and those 12 to 19 years of age (55.4%).
An estimated 33 600 000 adults ≥20 years of age have total serum cholesterol levels ≥240 mg/dL, with a prevalence of 15.0% (Table 13-1).
In 2008, an estimated 18 300 000 Americans had diagnosed diabetes mellitus, representing 8.0% of the adult population. An additional 7 100 000 had undiagnosed diabetes mellitus, and 36.8% had prediabetes, with abnormal fasting glucose levels. African Americans, Mexican Americans, Hispanic/Latino individuals, and other ethnic minorities bear a strikingly disproportionate burden of diabetes mellitus in the United States (Table 16-1).
The 2011 Update Expands Data Coverage of the Obesity Epidemic and Its Antecedents and Consequences
The estimated prevalence of overweight and obesity in US adults (≥20 years of age) is 149 300 000, which represents 67.3% of this group in 2008. Fully 33.7% of US adults are obese (body mass index ≥30 kg/m2). Men and women of all race/ethnic groups in the population are affected by the epidemic of overweight and obesity (Table 15-1).
Among children 2 to 19 years of age, 31.9% are overweight and obese (which represents 23 500 000 children), and 16.3% are obese (12 000 000 children). Mexican American boys and girls and African American girls are disproportionately affected. Over the past 3 decades, the prevalence of obesity in children 6 to 11 years of age has increased from ≈4% to more than 20%.
Obesity (body mass index ≥30 kg/m2) is associated with marked excess mortality in the US population. Even more notable is the excess morbidity associated with overweight and obesity in terms of risk factor development and incidence of diabetes mellitus, CVD end points (including coronary heart disease, stroke, and heart failure), and numerous other health conditions, including asthma, cancer, degenerative joint disease, and many others.
The prevalence of diabetes mellitus is increasing dramatically over time, in parallel with the increases in prevalence of overweight and obesity.
On the basis of NHANES 2003–2006 data, the age-adjusted prevalence of metabolic syndrome, a cluster of major cardiovascular risk factors related to overweight/obesity and insulin resistance, is 34% (35.1% among men and 32.6% among women).
The proportion of youth (≤18 years of age) who report engaging in no regular physical activity is high, and the proportion increases with age. In 2007, among adolescents in grades 9 through 12, 29.9% of girls and 17.0% of boys reported that they had not engaged in 60 minutes of moderate-to-vigorous physical activity, defined as any activity that increased heart rate or breathing rate, even once in the previous 7 days, despite recommendations that children engage in such activity ≥5 days per week.
Thirty-six percent of adults reported engaging in no vigorous activity (activity that causes heavy sweating and a large increase in breathing or heart rate).
Data from NHANES indicate that between 1971 and 2004, average total energy consumption among US adults increased by 22% in women (from 1542 to 1886 kcal/d) and by 10% in men (from 2450 to 2693 kcal/d; see Chart 19-1).
The increases in calories consumed during this time period are attributable primarily to greater average carbohydrate intake, in particular, of starches, refined grains, and sugars. Other specific changes related to increased caloric intake in the United States include larger portion sizes, greater food quantity and calories per meal, and increased consumption of sugar-sweetened beverages, snacks, commercially prepared (especially fast food) meals, and higher energy-density foods.
The 2011 Update Provides Critical Data Regarding Cardiovascular Quality of Care, Procedure Utilization, and Costs
In light of the current national focus on healthcare utilization, costs, and quality, it is critical to monitor and understand the magnitude of healthcare delivery and costs, as well as the quality of healthcare delivery, related to CVDs. The Update provides these critical data in several sections.
Quality-of-Care Metrics for CVDs
Chapter 20 reviews many metrics related to the quality of care delivered to patients with CVDs, as well as healthcare disparities. In particular, quality data are available from the AHA's “Get With The Guidelines” programs for coronary artery disease and heart failure and the American Stroke Association/ AHA's “Get With the Guidelines” program for acute stroke. Similar data from the Veterans Healthcare Administration, national Medicare and Medicaid data and National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network - “Get With The Guidelines” Registry data are also reviewed. These data show impressive adherence with guideline recommendations for many, but not all, metrics of quality of care for these hospitalized patients. Data are also reviewed on screening for cardiovascular risk factor levels and control.
Cardiovascular Procedure Utilization and Costs
Chapter 21 provides data on trends and current usage of cardiovascular surgical and invasive procedures. For example, the total number of inpatient cardiovascular operations and procedures increased 27%, from 5 382 000 in 1997 to 6 846 000 in 2007 (National Heart, Lung, and Blood Institute computation based on National Center for Health Statistics annual data).
Chapter 22 reviews current estimates of direct and indirect healthcare costs related to CVDs, stroke, and related conditions using Medical Expenditure Panel Survey data. The total direct and indirect cost of CVD and stroke in the United States for 2007 is estimated to be $286 billion. This figure includes health expenditures (direct costs, which include the cost of physicians and other professionals, hospital services, prescribed medications, home health care, and other medical durables) and lost productivity resulting from mortality (indirect costs). By comparison, in 2008, the estimated cost of all cancer and benign neoplasms was $228 billion ($93 billion in direct costs, $19 billion in morbidity indirect costs, and $116 billion in mortality indirect costs). CVD costs more than any other diagnostic group.
The AHA, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current data available in the Statistics Update. The 2007 mortality data have been released. More information can be found at the National Center for Health Statistics Web site, http://www.cdc.gov/nchs/data/nvsr/nvsr58/nvsr58_01.pdf.
Finally, it must be noted that this annual Statistical Update is the product of an entire year's worth of effort by dedicated professionals, volunteer physicians and scientists, and outstanding AHA staff members, without whom publication of this valuable resource would be impossible. Their contributions are gratefully acknowledged.
Note: Population data used in the compilation of NHANES prevalence estimates is for the latest year of the NHANES survey being used. Extrapolations for NHANES prevalence estimates are based on the census resident population for 2008 because this is the most recent year of NHANES data used in the Statistical Update.
↵* The findings and conclusions of this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.
The American Heart Association makes every effort to avoid any actual or potential conflicts of interest that may arise as a result of an outside relationship or a personal, professional, or business interest of a member of the writing panel. Specifically, all members of the writing group are required to complete and submit a Disclosure Questionnaire showing all such relationships that might be perceived as real or potential conflicts of interest.
The American Heart Association requests that this document be cited as follows: Roger VL, Go AS, Lloyd-Jones DM, Adams RJ, Berry JD, Brown TM, Carnethon MR, Dai S, de Simone G, Ford ES, Fox CS, Fullerton HJ, Gillespie C, Greenlund KJ, Hailpern SM, Heit JA, Ho PM, Howard VJ, Kissela BM, Kittner SJ, Lackland DT, Lichtman JH, Lisabeth LD, Makuc DM, Marcus GM, Marelli A, Matchar DB, McDermott MM, Meigs JB, Moy CS, Mozaffarian D, Mussolino ME, Nichol G, Paynter NP, Rosamond WD, Sorlie PD, Stafford RS, Turan TN, Turner MB, Wong ND, Wylie-Rosett J; on behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2011 update: a report from the American Heart Association. Circulation. 2011;123:e18–e209.
A copy of the statement is available at http://www.americanheart.org/presenter.jhtml?identifier=3003999 by selecting either the “topic list” link or the “chronological list” link (No. KB-0111). To purchase additional reprints, call 843-216-2533 or e-mail .
Expert peer review of AHA Scientific Statements is conducted at the AHA National Center. For more on AHA statements and guidelines development, visit http://www.americanheart.org/presenter.jhtml?identifier=3023366.
Permissions: Multiple copies, modification, alteration, enhancement, and/or distribution of this document are not permitted without the express permission of the American Heart Association. Instructions for obtaining permission are located at http://www.americanheart.org/presenter.jhtml?identifier=4431. A link to the “Permission Request Form” appears on the right side of the page.
- © 2011 American Heart Association, Inc.
1. About 1. About These Statistics
The American Heart Association (AHA) works with the Centers for Disease Control and Prevention's (CDC's) National Center for Health Statistics (NCHS); the National Heart, Lung, and Blood Institute (NHLBI); the National Institute of Neurological Disorders and Stroke (NINDS); and other government agencies to derive the annual statistics in this Update. This chapter describes the most important sources and the types of data we use from them. For more details, see Chapter 24 of this document, the Glossary.
The surveys used are:
Behavioral Risk Factor Surveillance System (BRFSS)—ongoing telephone health survey system
Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS)—stroke incidence rates and outcomes within a biracial population
Medical Expenditure Panel Survey (MEPS)—data on specific health services that Americans use, how frequently they use them, the cost of these services, and how the costs are paid
National Health and Nutrition Examination Survey (NHANES)—disease and risk factor prevalence and nutrition statistics
National Health Interview Survey (NHIS)—disease and risk factor prevalence
National Hospital Discharge Survey (NHDS)—hospital inpatient discharges and procedures (discharged alive, dead, or status unknown)
National Ambulatory Medical Care Survey (NAMCS)—physician office visits
National Hospital Ambulatory Medical Care Survey (NHAMCS)—hospital outpatient and emergency department visits
National Inpatient Sample (NIS) of the Agency for Healthcare Research and Quality (AHRQ)—hospital inpatient discharges, procedures, and charges
National Nursing Home Survey (NNHS)—nursing home residents
National Vital Statistics System—national and state mortality data
World Health Organization (WHO)—mortality rates by country
Youth Risk Behavior Surveillance System (YRBSS) (CDC)—health-risk behaviors in youth and young adults
Prevalence is an estimate of how many people have a disease at a given point or period in time. The NCHS conducts health examination and health interview surveys that provide estimates of the prevalence of diseases and risk factors. In this Update, the health interview part of the NHANES is used for the prevalence of cardiovascular diseases (CVDs). NHANES is used more than the NHIS because in NHANES, angina pectoris (AP) is based on the Rose Questionnaire; estimates are made regularly for heart failure (HF); hypertension is based on blood pressure (BP) measurements and interviews; and an estimate can be made for total CVD, including myocardial infarction (MI), AP, HF, stroke, and hypertension.
A major emphasis of this Update is to present the latest estimates of the number of people in the United States who have specific conditions to provide a realistic estimate of burden. Most estimates based on NHANES prevalence rates are based on data collected from 2005 to 2008 (in most cases, these are the latest published figure). These are applied to census population estimates for 2008. Differences in population estimates based on extrapolations of rates beyond the data collection period by use of more recent census population estimates cannot be used to evaluate possible trends in prevalence. Trends can only be evaluated by comparing prevalence rates estimated from surveys conducted in different years.
Risk Factor Prevalence
The NHANES 2005–2008 data are used in this Update to present estimates of the percentage of people with high lipid values, diabetes mellitus, overweight, and obesity. The NHIS is used for the prevalence of cigarette smoking and physical inactivity. Data for students in grades 9 through 12 are obtained from the YRBSS.
Incidence and Recurrent Attacks
An incidence rate refers to the number of new cases of a disease that develop in a population per unit of time. The unit of time for incidence is not necessarily 1 year, although we often discuss incidence in terms of 1 year. For some statistics, new and recurrent attacks or cases are combined. Our national incidence estimates for the various types of CVD are extrapolations to the US population from the Framingham Heart Study (FHS), the Atherosclerosis Risk in Communities (ARIC) study, and the Cardiovascular Health Study (CHS), all conducted by the NHLBI, as well as the GCNKSS, which is funded by the NINDS. The rates change only when new data are available; they are not computed annually. Do not compare the incidence or the rates with those in past editions of the Heart Disease and Stroke Statistics Update (also known as the Heart and Stroke Statistical Update for editions before 2005). Doing so can lead to serious misinterpretation of time trends.
Mortality data are presented according to the underlying cause of death. “Any-mention” mortality means that the condition was nominally selected as the underlying cause or was otherwise mentioned on the death certificate. For many deaths classified as attributable to CVD, selection of the single most likely underlying cause can be difficult when several major comorbidities are present, as is often the case in the elderly population. It is useful, therefore, to know the extent of mortality due to a given cause regardless of whether it is the underlying cause or a contributing cause (ie, its “any-mention” status). The number of deaths in 2007 with any mention of specific causes of death was tabulated by the NHLBI from the NCHS public-use electronic files on mortality.
The first set of statistics for each disease in this Update includes the number of deaths for which the disease is the underlying cause. Two exceptions are Chapter 7 (High Blood Pressure) and Chapter 9 (Heart Failure). High BP, or hypertension, increases the mortality risks of CVD and other diseases, and HF should be selected as an underlying cause only when the true underlying cause is not known. In this Update, hypertension and HF death rates are presented in 2 ways: (1) as nominally classified as the underlying cause and (2) as any-mention mortality.
National and state mortality data presented according to the underlying cause of death were computed from the mortality tables of the NCHS World Wide Web site, the Health Data Interactive data system of the NCHS, or the CDC compressed mortality file. Any-mention numbers of deaths were tabulated from the electronic mortality files of the NCHS World Wide Web site and from Health Data Interactive.
In this publication, we have used national population estimates from the US Census Bureau for 2008 in the computation of morbidity data. NCHS population estimates for 2007 were used in the computation of death rate data. The Census Bureau World Wide Web site1 contains these data, as well as information on the file layout.
Hospital Discharges and Ambulatory Care Visits
Estimates of the numbers of hospital discharges and numbers of procedures performed are for inpatients discharged from short-stay hospitals. Discharges include those discharged alive, dead, or with unknown status. Unless otherwise specified, discharges are listed according to the first-listed (primary) diagnosis, and procedures are listed according to all listed procedures (primary plus secondary). These estimates are from the NHDS of the NCHS unless otherwise noted. Ambulatory care visit data include patient visits to physician offices and hospital outpatient departments (OPDs) and emergency departments (EDs). Ambulatory care visit data reflect the first-listed (primary) diagnosis. These estimates are from NAMCS and NHAMCS of the NCHS.
International Classification of Diseases
Morbidity (illness) and mortality (death) data in the United States have a standard classification system: the International Classification of Diseases (ICD). Approximately every 10 to 20 years, the ICD codes are revised to reflect changes over time in medical technology, diagnosis, or terminology. Where necessary for comparability of mortality trends across the 9th and 10th ICD revisions, comparability ratios computed by the NCHS are applied as noted.2 Effective with mortality data for 1999, we are using the 10th revision (ICD-10). It will be a few more years before the 10th revision is used for hospital discharge data and ambulatory care visit data, which are based on the International Classification of Diseases, Clinical Modification, 9th Revision (ICD-9-CM).3
Prevalence and mortality estimates for the United States or individual states comparing demographic groups or estimates over time either are age specific or are age adjusted to the 2000 standard population by the direct method.4 International mortality data are age adjusted to the European standard.5 Unless otherwise stated, all death rates in this publication are age adjusted and are deaths per 100 000 population.
Data Years for National Estimates
In this Update, we estimate the annual number of new (incidence) and recurrent cases of a disease in the United States by extrapolating to the US population in 2008 from rates reported in a community- or hospital-based study or multiple studies. Age-adjusted incidence rates by sex and race are also given in this report as observed in the study or studies. For US mortality, most numbers and rates are for 2007. For disease and risk factor prevalence, most rates in this report are calculated from the 2005–2008 NHANES. Rates by age and sex are also applied to the US population in 2008 to estimate the numbers of people with the disease or risk factor in that year. Because NHANES is conducted only in the noninstitutionalized population, we extrapolated the rates to the total US population in 2008, recognizing that this probably underestimates the total prevalence, given the relatively high prevalence in the institutionalized population. The numbers and rates of hospital inpatient discharges for the United States are for 2007. Numbers of visits to physician offices, hospital EDs, and hospital OPDs are for 2007. Except as noted, economic cost estimates are for 2007.
For data on hospitalizations, physician office visits, and mortality, CVD is defined according to ICD codes given in Chapter 24 of the present document. This definition includes all diseases of the circulatory system, as well as congenital CVD. Unless so specified, an estimate for total CVD does not include congenital CVD. Prevalence of CVD includes people with hypertension, heart disease, stroke, peripheral artery disease, and diseases of the veins.
Data published by governmental agencies for some racial groups are considered unreliable because of the small sample size in the studies. Because we try to provide data for as many racial groups as possible, we show these data for informational and comparative purposes.
If you have questions about statistics or any points made in this Update, please contact the AHA National Center, Office of Science & Medicine ator 214-706-1423. Direct all media inquiries to News Media Relations at or 214-706-1173.
We do our utmost to ensure that this Update is error free. If we discover errors after publication, we will provide corrections at our World Wide Web site, http://www.americanheart.org/statistics, and in the journal Circulation.
US Census Bureau population estimates. Available at: http://www.census.gov/popest/national/asrh/files/NC-EST2008-ALLDATA-R-File14.csv. Accessed September 27, 2010.
National Center for Health Statistics. Health, United States, 2009, With Special Feature on Medical Technology. Hyattsville, Md: National Center for Health Statistics; 2010. Available at: http://www.cdc.gov/nchs/data/hus/hus09.pdf. Accessed July 30, 2010.
National Center for Health StatisticsCenters for Medicare and Medicaid Services. International Classification of Diseases, Ninth Revision: Clinical Modification (ICD-9-CM). Hyattsville, Md: National Center for Health Statistics; 1978.
World Health Organization. World Health Statistics Annual. Geneva, Switzerland: World Health Organization; 1998.
2. American Heart Association's 2020 Impact Goals
After achieving its major Impact Goals for 2010, the AHA recently created a new set of Impact Goals for the current decade.1 Specifically, the AHA committed to the following organizational goals:
By 2020, to improve the cardiovascular health of all Americans by 20%, while reducing deaths from cardiovascular disease and stroke by 20%.1
These goals include a novel concept, “cardiovascular health,” which encompasses 7 health behaviors and health factors (Table 2-1). “Ideal cardiovascular health” is defined by the absence of clinically manifest cardiovascular disease (CVD) and the simultaneous presence of optimal levels of all 7 health behaviors (lean body mass, avoidance of smoking, participation in physical activity, and healthy dietary intake consistent with a Dietary Approaches to Stop Hypertension [DASH]-like eating pattern) and health factors (untreated total cholesterol <200 mg/dL, untreated blood pressure <120/<80 mm Hg, and fasting blood glucose <100 mg/dL). Because the ideal cardiovascular health profile is known to be rare in the population, the entire spectrum of cardiovascular health can also be represented as being “ideal,” “intermediate,” or “poor” for each of the health behaviors and health factors, as shown in Table 2-1.1
Beginning in 2011, and recognizing the substantial time lag in the nationally representative data sets, the annual Statistical Update will begin to evaluate and publish metrics and information that gives AHA directional insights into progress and/or areas critical for greater concentration, to meet their 2020 goals. In this chapter, baseline data are presented that were derived from the existing national data available on January 20, 2010, the official announcement date of the 2020 Impact Goals.
Table 2-1 provides the specific definitions for ideal, intermediate, and poor cardiovascular health for each of the 7 health behaviors and health factors.
— Among children (Chart 2-1), the prevalence (unadjusted) of ideal levels of cardiovascular health behaviors and factors currently varies from 0% for the healthy diet score (ie, essentially no children meet 4 or 5 of the 5 dietary components) to more than 80% for the smoking and fasting glucose metrics. More than 90% of US children meet 0 or only 1 of the 5 healthy dietary components.
— Among US adults (Chart 2-2), the age-standardized prevalence of ideal levels of cardiovascular health behaviors and factors currently varies from 0.2% for the healthy diet score up to 72% for the smoking metric (ie, 72% of US adults have never smoked or are current nonsmokers who have quit for more than 12 months).
— In general, the prevalence of ideal levels of health behaviors and health factors is higher in US children than in US adults.
Age-standardized and age-specific prevalence estimates for Ideal Cardiovascular Health and for ideal levels of each of its components are shown in Table 2-2.
Chart 2-3 displays the prevalence estimates for the population of US children meeting different numbers of criteria for Ideal Cardiovascular Health (out of 7 possible).
— Half of US children ages 12 to 19 years meet 4 or fewer criteria for Ideal Cardiovascular Health.
— The distributions are similar in boys and girls.
Charts 2-4 and 2-5 display the age-standardized prevalence estimates for the population of US adults meeting different numbers of criteria for Ideal Cardiovascular Health (out of 7 possible), overall, and stratified by age groups, sex, and race.
— Approximately 3% of US adults have 0 of the 7 criteria at ideal levels, with ≈26% having 3 at ideal levels (Chart 2-4).
— Compared with younger adults, older adults tend to have fewer of the 7 metrics at ideal levels; more than half of those over age 60 years have only 2 or fewer at ideal levels (Chart 2-4).
— Women tend to have more metrics at ideal levels than do men (Chart 2-4).
— Approximately 61% of white adults and 71% of black and Mexican American adults have 3 or fewer metrics (out of 7) at ideal levels (Chart 2-5).
Chart 2-6 displays the age-standardized percentages of US adults and percentages of children who have 5 or more of the metrics (out of 7 possible) at ideal levels.
— Almost 50% of US children aged 12 to 19 years have 5 or more metrics at ideal levels, including somewhat more boys than girls.
— However, only 17% of US adults have 5 or more metrics with ideal levels, including 11% of men and 24% of women.
— Whites have approximately twice the percentage of adults with 5 or more metrics with ideal levels, compared with Mexican Americans.
In 2006 (baseline data for the 2020 Impact Goals on CVD and stroke mortality), age-standardized death rate from all CVDs was 262.5 per 100 000 (Chart 2-7).
— Death rates from stroke, heart diseases and other cardiovascular causes were 43.6, 200.2, and 53.9 per 100 000, respectively.2
Data from NHANES 1999–2006 reveal that, overall, 8.1% of Americans self-reported having some type of CVD (Table 2-3).
Among those with CVD, risk factor prevalence, awareness, treatment, and control were variable (Table 2-3).
— Nearly 37% were current smokers or had quit for less than 12 months.
— Awareness and treatment of hypertension were ≈80%, but only two-thirds of those who were treated were controlled to goal levels.
— Awareness and treatment of hypercholesterolemia were 60% and 68%, respectively, and 80% of treated individuals were at goal cholesterol levels.
— More than three fourths were overweight or obese, and 45% were obese.
— 18% had diabetes mellitus.
— 45% participated in no physical activity.
— 100% of those with CVD met 3 or fewer of the 5 components of the healthy diet score.
Taken together, these baseline data indicate the substantial progress that will need to occur for the AHA to achieve its 2020 Impact Goals over the next decade.
— To achieve improvements in cardiovascular health, all segments of the population will need to focus on improved cardiovascular health behaviors, in particular, with regard to diet and weight, as well as on an increase in physical activity and further reduction of the prevalence of smoking.
— More children, adolescents, and young adults will need to learn how to preserve their ideal levels of cardiovascular health factors and health behaviors into older ages.
— With regard to reducing the burden of CVD and stroke morbidity and mortality, renewed emphasis will be needed on treatment of acute events as well as secondary and primary prevention through treatment and control of risk factors.
Future issues of the Statistical Update will track progress toward these goals.
- Lloyd-Jones DM,
- Hong Y,
- Labarthe D,
- Mozaffarian D,
- Appel LJ,
- Van Horn L,
- Grenlund K,
- Daniels S,
- Nichol G,
- Tomaselli GF,
- Arnett DK,
- Fonarow GC,
- Ho PM,
- Lauer MS,
- Masoudi FA,
- Robertson RM,
- Roger V,
- Schwamm LH,
- Sorlie P,
- Yancy CW,
- Rosamond WD
- Heron MP,
- Hoyert DL,
- Murphy SL,
- Xu JQ,
- Kochanek KD,
- Tejada-Vera B
3. Cardiovascular Diseases
An estimated 82 600 000 American adults (>1 in 3) have 1 or more types of CVD. Of these, 40 400 000 are estimated to be ≥60 years of age. Total CVD includes diseases listed in the bullet points below, with the exception of congenital CVD. Because of overlap, it is not possible to add these conditions to arrive at a total.
High blood pressure (HBP)—76 400 000 (defined as systolic pressure ≥140 mm Hg and/or diastolic pressure ≥90 mm Hg, use of antihypertensive medication, or being told at least twice by a physician or other health professional that one has HBP).
Coronary heart disease (CHD)—16 300 000
— MI (heart attack)— 7 900 000
— AP (chest pain)— 9 000 000
HF—5 700 000
Stroke— 7 000 000
Congenital cardiovascular defects— 650 000 to 1 300 000
The following age-adjusted prevalence estimates from the NHIS, NCHS are for diagnosed conditions for people ≥18 years of age in 20091:
Among whites only, 11.9% have heart disease (HD), 6.4% have CHD, 23.0% have hypertension, and 2.5% have had a stroke.
Among blacks or African Americans, 11.2% have HD, 6.7% have CHD, 32.2% have hypertension, and 3.8% have had a stroke.
Among Hispanics or Latinos, 8.5% have HD, 5.8% have CHD, 21.5% have hypertension, and 2.0% have had a stroke.
Among Asians, 6.3% have HD, 3.9% have CHD, 19.4% have hypertension, and 1.3% have had a stroke.
Among American Indians or Alaska Natives, 8.0% have HD, 4.1% (figure considered unreliable) have CHD, and 21.8% have hypertension. An estimate for stroke is not reported because of its large relative standard error.
Among Native Hawaiians or other Pacific Islanders, HD, CHD, and stroke numbers are not reported because of large relative standard errors; 22.0% have hypertension, but the figure is considered unreliable.
Asian Indian adults (9%) are ≈2-fold more likely than Korean adults (4%) to have ever been told they have HD, based on data for 2004 to 2006.2
On the basis of the NHLBI's FHS original and offspring cohort data from 1980 to 20033:
— The average annual rates of first cardiovascular events rise from 3 per 1000 men at 35 to 44 years of age to 74 per 1000 men at 85 to 94 years of age. For women, comparable rates occur 10 years later in life. The gap narrows with advancing age.
— Before 75 years of age, a higher proportion of CVD events due to CHD occur in men than in women, and a higher proportion of events due to stroke occur in women than in men.
Among American Indian men 45 to 74 years of age, the incidence of CVD ranges from 15 to 28 per 1000 population. Among women, it ranges from 9 to 15 per 1000.4
Data from the FHS indicate that the subsequent lifetime risk for all CVD in recipients starting free of known disease is 2 in 3 for men and >1 in 2 for women at 40 years of age (personal communication, Donald Lloyd-Jones, MD, Northwestern University, Chicago, Ill) (see Table 3-4).
Analysis of FHS data among participants free of CVD at 50 years of age showed the lifetime risk for developing CVD was 51.7% for men and 39.2% for women. Median overall survival was 30 years for men and 36 years for women.5
ICD-10 I00–I99, Q20–Q28 for CVD (CVD mortality includes congenital cardiovascular defects); C00–C97 for cancer; C33–C34 for lung cancer; C50 for breast cancer; J40–J47 for chronic lower respiratory disease (CLRD); G30 for Alzheimer disease; E10–E14 for diabetes mellitus (DM); and V01–X59, Y85–Y86 for accidents.
Mortality data show that CVD (I00–I99, Q20–Q28) as the underlying cause of death (including congenital cardiovascular defects) accounted for 33.6% (813 804) of all 2 423 712 deaths in 2007, or 1 of every 3 deaths in the United States. CVD any-mentions (1 342 314 deaths in 2007) constituted 55.4% of all deaths that year (NHLBI; NCHS public-use data files).6 The 2007 death rate was 251.2 (excluding congenital cardiovascular defects) (NCHS).6 In every year since 1900 except 1918, CVD accounted for more deaths than any other major cause of death in the United States.7–10
On average, >2200 Americans die of CVD each day, an average of 1 death every 39 seconds. CVD claims more lives each year than cancer, CLRD, and accidents combined.6
The 2007 overall death rate due to CVD (I00–I99) was 251.2. The rates were 294.0 for white males, 405.9 for black males, 205.7 for white females, and 286.1 for black females. From 1997 to 2007, death rates due to CVD (ICD-10 I00–I99) declined 27.8%. In the same 10-year period, the actual number of CVD deaths per year declined 14.2% (NHLBI tabulation).6 (Appropriate comparability ratios were applied.)
Among other causes of death in 2007, cancer caused 562 875 deaths; accidents, 123 706; Alzheimer disease, 74 632; and HIV/AIDS, 11 295.6
The 2007 CVD (I00–I99) death rates were 300.3 for males and 211.6 for females. Death rates for cancer (malignant neoplasms) were 217.5 for males and 151.3 for females. Breast cancer claimed the lives of 40 599 females in 2007; lung cancer claimed 70 388. Death rates for females were 22.9 for breast cancer and 40.0 for lung cancer. One in 30 deaths in females was due to breast cancer, whereas 1 in 6.4 was due to CHD. For comparison, 1 in 4.5 females died of cancer, whereas 1 in 2.9 died of CVD (I00–I99, Q20–Q28). On the basis of 2007 mortality data, CVD caused ≈1 death per minute among females, or 421 918 deaths in females in 2007. That represents more female lives than were claimed by cancer, CLRD, Alzheimer disease, and accidents combined (unpublished NHLBI tabulation).6
More than 150 000 Americans died of CVD (I00–I99) in 2007 who were <65 years of age, and nearly 33% of deaths owing to CVD occurred before the age of 75 years, which is well before the average life expectancy of 77.9 years.6
In 2007, death rates for diseases of the heart in American Indians or Alaska Natives were 159.8 for males and 99.8 for females; for Asians or Pacific Islanders, they were 126.0 for males and 82.0 for females; and for Hispanics or Latinos, they were 165.0 for males and 111.8 for females.7
According to the NCHS, if all forms of major CVD were eliminated, life expectancy would rise by almost 7 years. If all forms of cancer were eliminated, the estimated gain would be 3 years. According to the same study, the probability at birth of eventually dying of major CVD (I00–I78) is 47%, and the chance of dying of cancer is 22%. Additional probabilities are 3% for accidents, 2% for DM, and 0.7% for HIV.11
In 2007, the leading causes of death in women ≥65 years of age were diseases of the heart (No. 1), cancer (No. 2), stroke (No. 3), and CLRD (No. 4). In older men, they were diseases of the heart (No. 1), cancer (No. 2), CLRD (No. 3), and stroke (No. 4).6,10
A study of the decrease in US deaths due to CHD from 1980 to 2000 suggests that ≈47% of the decrease was attributable to increased use of evidence-based medical therapies and 44% to changes in risk factors in the population due to lifestyle and environmental changes.12
Analysis of data from NCHS was used to determine the number of disease-specific deaths attributable to all nonoptimal levels of each risk factor exposure, by age and sex. In 2005, tobacco smoking and high BP were estimated to be responsible for 467 000 deaths, accounting for ≈1 in 5 or 6 deaths among US adults. Overweight/obesity and physical inactivity were each estimated to be responsible for nearly 1 in 10 deaths. High dietary salt, low dietary omega-3 fatty acids, and high dietary trans fatty acids were the dietary risks with the largest estimated mortality effects.13
Among an estimated 45 million people with functional disabilities in the United States, HD, stroke, and hypertension are among the 15 leading conditions that caused those disabilities. Disabilities were defined as difficulty with activities of daily living or instrumental activities of daily living, specific functional limitations (except vision, hearing, or speech), and limitation in ability to do housework or work at a job or business.14
Out-of-Hospital Cardiac Arrest
There is a wide variation in the reported incidence of and outcome for out-of-hospital cardiac arrest. These differences are due in part to differences in definition and ascertainment of cardiac arrest data, as well as differences in treatment after the onset of cardiac arrest. Cardiac arrest is defined as cessation of cardiac mechanical activity and is confirmed by the absence of signs of circulation.15
Extrapolation of the mortality rate observed in the Resuscitation Outcomes Consortium (ROC) to the total population of the United States suggests that each year, there are 295 000 (quasi confidence intervals 236 000 to 325 000) emergency medical services (EMS)-assessed out-of-hospital cardiac arrests in the United States.16
≈60% of out-of-hospital cardiac deaths are treated by EMS personnel.17
Only 33% of those with EMS-treated out-of-hospital cardiac arrest have symptoms within 1 hour of death.18
Among EMS-treated out-of-hospital cardiac arrests, 23% have an initial rhythm of ventricular fibrillation (VF), ventricular tachycardia (VT), or are shockable by automated external defibrillator (AED); 31% receive bystander cardiopulmonary resuscitation (CPR).16
The incidence of cardiac arrest with an initial rhythm of VF is decreasing over time; however, the incidence of cardiac arrest with any initial rhythm is not decreasing.19
Among ROC sites between December 2005 and May 2007, 32.0% of out-of-hospital cardiac arrests received lay-responder CPR and only 2.1% had an AED applied before EMS arrival. Overall chance of surviving until hospital discharge was 7%, and AED application was associated with a moderately increased odds of survival.20
The median survival rate to hospital discharge after EMS-treated out-of-hospital cardiac arrest with any first recorded rhythm is 7.9%.16
The median survival rate after VF is 21%.16
Extrapolation of data from ARIC, CHS, and Framingham suggests that there are 125 000 CHD deaths within 1 hour of symptom onset (NHLBI, written communication, July 13, 2010).
A study conducted in New York City found the age-adjusted incidence of out-of-hospital cardiac arrest per 10 000 adults was 10.1 among blacks, 6.5 among Hispanics, and 5.8 among whites. The age-adjusted survival to 30 days after discharge was more than twice as poor for blacks as for whites, and survival among Hispanics was also lower than among whites.26
In a systematic review of literature through 2008, the factors most correlated with survival to hospital discharge following out-of-hospital cardiac arrest were witness by a bystander, witness by EMS, receipt of bystander CPR, being found in VF or VT, and achieving return of spontaneous circulation.27
Out-of-Hospital Cardiac Arrest: Children
The reported incidence of out-of-hospital pediatric cardiac arrest varies widely (≈8 per 100 000).28
There are >74 million individuals <18 years of age in the United States29; this implies that there are about 5920 pediatric out-of-hospital cardiac arrests annually of all causes (including trauma, sudden infant death syndrome, respiratory causes, cardiovascular causes, and submersion).
Seven percent of EMS-treated pediatric cardiac arrest patients had an initial rhythm of VF, VT, or were shockable by AED; 35% received bystander CPR.28
Studies that document voluntary reports of deaths among high school athletes suggest that the incidence of out-of-hospital cardiac arrest ranges from 0.28 to 1.0 deaths per 100 000 high school athletes annually nationwide.30,31 Although incomplete, these numbers provide a basis for estimating the number of deaths in this age range.
One report describes the incidence of nontraumatic pediatric cardiac arrest (among students 3 to 18 years of age) that occurs in schools and estimates rates (per 100 000 person-school-years) for elementary, middle, and high schools to be 0.18, 0.19, and 0.15, respectively, for the geographic area (King County, WA) and time frame (January 1, 1990, to December 31, 2005) studied.32
The reported average rate of survival to hospital discharge after pediatric out-of-hospital cardiac arrest is 6%.
Most sudden deaths in athletes were attributable to CVD (56%). Of the cardiovascular deaths that occurred, 29% occurred in blacks, 54% in high school students, and 82% with physical exertion during competition/training, and only 11% occurred in females, although this proportion has increased over time.33
In-Hospital Cardiac Arrest
A total of 287 facilities reported 18 817 events to the National Registry for Cardiopulmonary Resuscitation during 2009.
— The rates of survival to discharge after in-hospital cardiac arrest were 33% among children and 21% among adults. Of these, 95% were monitored or witnessed.
— Eighteen percent had VF or pulseless VT as the first recorded rhythm. Of these, 43% survived to discharge.
Awareness of CPR
Seventy-nine percent of the lay public are confident that they know what actions to take in a medical emergency; 98% recognize an AED as something that administers an electric shock to restore a normal heart beat among victims of sudden cardiac arrest; and 60% are familiar with CPR (Harris Interactive survey conducted on behalf of the AHA among 1132 US residents 18 years of age and older, January 8, 2008, through January 21, 2008).
Awareness of Warning Signs and Risk Factors for CVD
Surveys conducted by the AHA in 1997, 2000, 2003, and 2006 to evaluate trends in women's awareness, knowledge, and perceptions related to CVD found that, in 2006, awareness of HD as the leading cause of death among women was 57%, significantly higher than in prior surveys. Awareness was lower among black and Hispanic women than among white women, and the racial/ethnic difference has not changed appreciably over time. In 2006, more than twice as many women felt uninformed about stroke compared with HD. Hispanic women were more likely than white women to report that there is nothing they can do to keep themselves from getting CVD. The majority of respondents reported confusion related to basic CVD prevention strategies.34
A nationally representative sample of women responded to a questionnaire about history of CVD risk factors, self-reported actions taken to reduce risk, and barriers to heart health. According to the study, published in 2006, the rate of awareness of CVD as the leading cause of death had nearly doubled since 1997, was significantly greater for whites than for blacks and Hispanics, and was independently correlated with increased physical activity (PA) and weight loss in the previous year. Fewer than half of the respondents were aware of healthy levels of risk factors. Awareness that their personal level was not healthy was positively associated with preventive action. Most women took steps to lower risk in family members and themselves.35
A total of 875 students in 4 Michigan high schools were given a survey to obtain data on the perception of risk factors and other knowledge-based assessment questions about CVD. Accidents were rated as the greatest perceived lifetime health risk (39%). Nearly 17% selected CVD as the greatest lifetime risk, which made it the third most popular choice after accidents and cancer. When asked to identify the greatest cause of death for each sex, 42% correctly recognized CVD for men, and 14% correctly recognized CVD for women; 40% incorrectly chose abuse/use behavior with a substance other than cigarettes as the most important CVD risk behavior.36
Data from the 2003 CDC BRFSS survey of adults ≥18 years of age showed the prevalence of respondents who reported having ≥2 risk factors for HD and stroke was successively higher at higher age groups. The prevalence of having ≥2 risk factors was highest among blacks (48.7%) and American Indians/Alaska Natives (46.7%) and lowest among Asians (25.9%); prevalence was similar in women (36.4%) and men (37.8%). The prevalence of multiple risk factors ranged from 25.9% among college graduates to 52.5% among those with less than a high school diploma (or its equivalent). People reporting household income of ≥$50 000 had the lowest prevalence (28.8%), and those reporting household income of $10 000 had the highest prevalence (52.5%). Adults who reported being unable to work had the highest prevalence (69.3%) of ≥2 risk factors, followed by retired people (45.1%), unemployed adults (43.4%), homemakers (34.3%), and employed people (34.0%). Prevalence of ≥2 risk factors varied by state/territory and ranged from 27.0% (Hawaii) to 46.2% (Kentucky). Twelve states and 2 territories had a multiple-risk-factor prevalence of ≥40%: Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, Ohio, Oklahoma, Tennessee, West Virginia, Guam, and Puerto Rico.37
Data from the Chicago Heart Association Detection Project (1967 to 1973, with an average follow-up of 31 years) showed that in younger women (18 to 39 years of age) with favorable levels for all 5 major risk factors (BP, serum cholesterol, body mass index [BMI], DM, and smoking), future incidence of CHD and CVD is rare, and long-term and all-cause mortality are much lower than for those who have unfavorable or elevated risk factor levels at young ages. Similar findings applied to men in this study.38,39
Analysis of several data sets by the CDC showed that in adults ≥18 years of age, disparities were common in all risk factors examined. In men, the highest prevalence of obesity (29.7%) was found in Mexican Americans who had completed a high school education. Black women with or without a high school education had a high prevalence of obesity (48.4%). Hypertension prevalence was high among blacks (41.2%) regardless of sex or educational status. Hypercholesterolemia was high among white and Mexican American men and white women regardless of educational status. CHD and stroke were inversely related to education, income, and poverty status. Hospitalization for total HD and acute MI was greater among men, but hospitalization for congestive heart failure (CHF) and stroke was greater among women. Among Medicare enrollees, CHF hospitalization was higher in blacks, Hispanics, and American Indians/Alaska Natives than among whites, and stroke hospitalization was highest in blacks. Hospitalizations for CHF and stroke were highest in the southeastern United States. Life expectancy remains higher in women than in men and in whites than in blacks by ≈5 years. CVD mortality at all ages tended to be highest in blacks.40
Analysis of 5 cross-sectional, nationally representative surveys from the National Health Examination Survey (NHES) 1960–1962 to the NHANES 1999–2000 showed that the prevalence of key risk factors (ie, high cholesterol, HBP, current smoking, and total DM) decreased over time across all BMI groups, with the greatest reductions observed among overweight and obese groups. Total DM prevalence was stable within BMI groups over time; however, the trend has leveled off or been reversed for some of the risk factors in more recent years.41
Data from BRFSS 2006–2008 demonstrated that during this 3-year period, 25.6% of non-Hispanic blacks, non-Hispanic whites, and Hispanics were obese, but prevalent obesity varied across groups: 35.7% for non-Hispanic blacks, 28.7% for Hispanics, and 23.7% for non-Hispanic whites.
Data from NHANES 2005–2006 showed that only 9.6% of US adults met their recommended target of daily dietary sodium intake.42
Analysis of >14 000 middle-aged subjects in the ARIC study sponsored by the NHLBI showed that >90% of CVD events in black subjects, compared with ≈70% in white subjects, appeared to be explained by elevated or borderline risk factors. Furthermore, the prevalence of participants with elevated risk factors was higher in black subjects; after accounting for education and known CVD risk factors, the incidence of CVD was identical in black and white subjects. Thus, the observed higher CVD incidence rate in black subjects appears to be largely attributable to a greater prevalence of elevated risk factors. These results suggest that the primary prevention of elevated risk factors might substantially impact the future incidence of CVD, and these beneficial effects would likely be applicable not only for white but also for black subjects.43
Data from the MEPS 2004 Full-Year Data File showed that nearly 26 million US adults ≥18 years of age were told by a doctor that they had HD, stroke, or any other heart-related disease44:
— 56.6% of those surveyed said they engaged in moderate-to-vigorous PA 3 times per week; 57.9% of those surveyed who had not been told they had HD engaged in regular PA, more than those who had been told they had HD (46.3%).
— 38.6% maintained a healthy weight. Among those told that they had HD, 33.9% had a healthy weight compared with 39.3% who had never been told they had HD.
— 78.8% did not currently smoke. Among those ever told that they had indicators of HD, 18.3% continued to smoke.
— More than 93% engaged in at least 1 recommended behavior for prevention of HD: 75.5% engaged in 1 or 2; 18% engaged in all 3; and 6.5% did not engage in any of the recommended behaviors.
— Age-based variations:
∘ Moderate to vigorous PA ≥3 times per week varied according to age. Younger people (18 to 44 years of age) were more likely (59.9%) than those who were older (45 to 64 and ≥65 years of age, 55.3% and 48.5%, respectively) to engage in regular PA.
∘ A greater percentage of those 18 to 44 years of age had a healthy weight (43.7%) than did those 45 to 64 years of age and ≥65 years of age (31.4% and 37.3%, respectively).
∘ People ≥65 years of age were more likely to be current nonsmokers (89.7%) than were people 18 to 44 years of age and 45 to 64 years of age (76.1% and 77.7%, respectively).
— Race/ethnicity-based variations:
∘ Non-Hispanic whites were more likely than Hispanics or non-Hispanic blacks to engage in moderate-to-vigorous PA (58.5% versus 51.4% and 52.5%, respectively).
∘ Non-Hispanic whites were more likely to have maintained a healthy weight than were Hispanics or non-Hispanic blacks (39.8% versus 32.1% and 29.7%, respectively).
∘ Hispanics were more likely to be nonsmokers (84.2%) than were non-Hispanic whites and non-Hispanic blacks (77.8% and 76.3%, respectively).
— Sex-based variations:
∘ Men were more likely to have engaged in moderate-to-vigorous PA ≥3 times per week than women (60.3% versus 53.1%, respectively).
∘ Women were more likely than men to have maintained a healthy weight (45.1% versus 31.7%, respectively).
∘ 81.7% of women did not currently smoke, compared with 75.7% of men.
— Variations based on education level:
∘ A greater percentage of adults with at least some college education engaged in moderate-to-vigorous PA ≥3 times per week (60.8%) than did those with a high school education or less than a high school education (55.3% and 48.3%, respectively).
∘ A greater percentage of adults with at least some college education had a healthy weight (41.2%) than did those with a high school or less than high school education (36.2% and 36.1%, respectively).
∘ There was a greater percentage of nonsmokers among those with a college education (85.5%) than among those with a high school or less than high school education (73.8% and 69.9%, respectively).
Participants (18 to 64 years of age at baseline) in the Chicago Heart Association Detection Project in Industry without a history of MI were investigated to determine whether traditional CVD risk factors were similarly associated with CVD mortality in black and white men and women. In general, the magnitude and direction of associations were similar by race. Most traditional risk factors demonstrated similar associations with mortality in black and white adults of the same sex. Small differences were primarily in the strength and not the direction of the association.45
A study of nearly 1500 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) study found that Hispanics with hypertension, hypercholesterolemia, and/or DM who speak Spanish at home and/or have spent less than half a year in the United States have higher systolic BP, low-density lipoprotein (LDL) cholesterol, and fasting blood glucose, respectively, than Hispanics who speak English and who have lived a longer period of time in the United States.46
Family History of Premature-Onset CVD
There is consistent evidence from multiple large-scale prospective epidemiology studies for a strong and significant association of a reported family history of premature parental CHD with incident MI or CHD in offspring. In the FHS, the occurrence of a validated premature atherosclerotic CVD event in either a parent47 or a sibling48 was associated with an ≈2-fold elevated risk for CVD, independent of other traditional risk factors.
Addition of family history of premature CVD to a model that contained traditional risk factors provided modestly improved prognostic value in the FHS.47 Family history of premature MI is also an independent risk factor in other multivariable risk models that contain traditional risk factors in large cohorts of women50 and men.50
In the FHS, a parental history of validated HF is associated with a 1.7-fold higher risk of HF in offspring, after multivariable adjustment.53
A family history of early-onset sudden cardiac death in a first-degree relative is associated with a >2-fold higher risk for sudden cardiac death in offspring on the basis of available case-control studies.54
The 2004 HealthStyles survey of 4345 people in the United States indicated that most respondents believe that knowing their family history is important for their own health, but few are aware of the specific health information from relatives necessary to develop a family history.55
An accurate and complete family history may identify rare mendelian conditions such as hypertrophic cardiomyopathy, long-QT syndrome, or familial hypercholesterolemia. However, in most people with a family history of a CVD event, a known rare mendelian condition is not identified.
Studies are under way to determine genetic variants that may help identify people at increased risk of CVD.
Impact of Healthy Lifestyle and Low Risk Factor Levels
Much of the literature on CVD has focused on factors associated with increasing risk for CVD and on factors associated with poorer outcomes in the presence of CVD; however, in recent years, a number of studies have defined the potential beneficial effects of healthy lifestyle factors and lower CVD risk factor burden on CVD outcomes and longevity. These studies suggest that prevention of risk factor development at younger ages may be the key to “successful aging,” and they highlight the need for intensive prevention efforts at younger and middle ages once risk factors develop to increase the likelihood of healthy longevity.
The lifetime risk for CVD and median survival were highly associated with risk factor presence and burden at 50 years of age among >7900 men and women from the FHS followed up for 111 000 person-years. In this study, optimal risk factor burden at 50 years of age was defined as BP <120/ 80 mm Hg, total cholesterol <180 mg/dL, absence of DM, and absence of smoking. Elevated risk factors were defined as stage 1 hypertension or borderline high cholesterol (200 to 239 mg/dL). Major risk factors were defined as stage 2 hypertension, elevated cholesterol (≥240 mg/dL), current smoking, and DM. Remaining lifetime risks for atherosclerotic CVD events were only 5.2% in men and 8.2% in women with optimal risk factors at 50 years of age compared with 68.9% in men and 50.2% in women with ≥2 major risk factors at age 50. In addition, men and women with optimal risk factors had a median life expectancy ≥10 years longer than those with ≥2 major risk factors at age 50 years.5
A recent study examined the association between low lifetime predicted risk for CVD (ie, having all optimal or near-optimal risk factor levels) and burden of subclinical atherosclerosis in younger adults in the Coronary Artery Risk Development in Young Adults (CARDIA) and MESA studies of the NHLBI. Among participants <50 years of age, nearly half had low and half had high predicted lifetime risks for CVD. Those with low predicted lifetime risk had lower prevalence and less severe amounts of coronary calcification and less carotid intima-media thickening, even at these younger ages, than those with high predicted lifetime risk. During follow-up, those with low predicted lifetime risk also had less progression of coronary calcium.56
In another study, FHS investigators followed up 2531 men and women who were examined between the ages of 40 and 50 years and observed their overall rates of survival and survival free of CVD to 85 years of age and beyond. Low levels of the major risk factors in middle age was associated with overall survival and morbidity-free survival to 85 years of age or more.57
— Overall, 35.7% survived to the age of 85 years, and 22% survived to that age free of major morbidities.
— Factors associated with survival to the age of 85 years included female sex, lower systolic BP, lower total cholesterol, better glucose tolerance, absence of current smoking, and higher level of education attained. Factors associated with survival to the age of 85 years free of MI, unstable angina, HF, stroke, dementia, and cancer were nearly identical.
— When adverse levels of 4 of these factors were present in middle age, <5% of men and ≈15% of women survived to 85 years of age.
A study of 366 000 men and women from the Multiple Risk Factor Intervention Trial (MRFIT) and Chicago Heart Association Detection Project in Industry defined low-risk status as follows: serum cholesterol level <200 mg/dL, untreated BP 120/80 mm Hg, absence of current smoking, absence of DM, and absence of major electrocardiographic abnormalities. Compared with those who did not have low risk factor burden, those with low risk factor burden had between 73% and 85% lower relative risk (RR) for CVD mortality, 40% to 60% lower relative total mortality rates, and 6 to 10 years' longer life expectancy.39
A study of 84 129 women enrolled in the Nurses' Health Study identified 5 healthy lifestyle factors, including absence of current smoking, drinking half a glass or more of wine per day (or equivalent alcohol consumption), half an hour or more per day of moderate or vigorous PA, BMI <25 kg/m2, and dietary score in the top 40% (which included diets with lower amounts of trans fats, lower glycemic load, higher cereal fiber, higher marine omega-3 fatty acids, higher folate, and higher polyunsaturated to saturated fat ratio). When 3 of the 5 healthy lifestyle factors were present, the RR for CHD over a 14-year period was 57% lower; when 4 were present, RR was 66% lower; and when all 5 factors were present, RR was 83% lower.58 However, data from NHANES 1999–2002 showed that only about one third of adults complied with 6 or more of the recommended heart-healthy behaviors. Dietary recommendations, in general, and daily fruit intake recommendations, in particular, were least likely to be followed.59
In the Chicago Heart Association Detection Project in Industry, remaining lifetime risks for CVD death were noted to increase substantially and in a graded fashion according to the number of risk factors present in middle age (40 to 59 years of age). However, remaining lifetime risks for non-CVD death also increased dramatically with increasing CVD risk factor burden. These data help to explain the markedly greater longevity experienced by those who reach middle age free of major CVD risk factors.60
Among individuals 70 to 90 years of age, adherence to a Mediterranean-style diet and greater PA are associated with 65% to 73% relatively lower rates of all-cause mortality, as well as lower mortality rates due to CHD, CVD, and cancer.61
Seventeen-year mortality data from the NHANES II Mortality Follow-Up Study indicated that the RR for fatal CHD was 51% lower for men and 71% lower for women with none of 3 major risk factors (hypertension, current smoking, and elevated total cholesterol [≥ 240 mg/dL]) than for those with 1 or more risk factors. Had all 3 major risk factors not occurred, it is hypothesized that 64% of all CHD deaths among women and 45% of CHD deaths in men could have been avoided.62
Investigators from the Chicago Heart Association Detection Project in Industry have also observed that risk factor burden in middle age is associated with better quality of life at follow-up in older age (≈25 years later) and lower average annual Medicare costs at older ages.
— The presence of a greater number of risk factors in middle age is associated with lower scores at older ages on assessment of social functioning, mental health, walking, and health perception in women, with similar findings in men.63
— Similarly, the existence of a greater number of risk factors in middle age is associated with higher average annual CVD-related and total Medicare costs (once Medicare eligibility is attained).64
Hospital Discharges, Ambulatory Care Visits, and Nursing Home Residents
From 1997 to 2007, the number of inpatient discharges from short-stay hospitals with CVD as the first-listed diagnosis decreased from 6 097 000 to 5 890 000 (NHDS, NCHS, and NHLBI). In 2007, CVD ranked highest among all disease categories in hospital discharges. (NHDS, NCHS, and NHLBI).
In 2008, there were 91 736 000 physician office visits with a primary diagnosis of CVD (NCHS, NAMCS).65 In 2008, there were 4 866 000 ED visits with a primary diagnosis of CVD (NCHS, National Hospital Ambulatory Medical Care Survey [NHAMCS]).66
In 2008, there were 8 795 000 hospital OPD visits with a primary diagnosis of CVD (NHAMCS).66 In 2005, ≈1 of every 6 hospital stays, or almost 6 million, resulted from CVD (AHRQ, NIS). The total inpatient hospital cost for CVD was $71.2 billion, approximately one fourth of the total cost of inpatient hospital care in the United States. The average cost per hospitalization was ≈41% higher than the average cost for all stays. Hospital admissions that originated in the ED accounted for 60.7% of all hospital stays for CVD. This was 41% higher than the overall rate of 43.1%; 3.3% of patients admitted to the hospital for CVD died in the hospital, which was significantly higher than the average in-hospital death rate of 2.1%.67
In 2004, coronary atherosclerosis was estimated to be responsible for 1.2 million hospital stays and was the most expensive condition treated. This condition resulted in >$44 billion in expenses. More than half of the hospital stays for coronary atherosclerosis were among patients who also received percutaneous coronary intervention or cardiac revascularization (coronary artery bypass graft; CABG) during their stay. Acute MI resulted in $31 billion of inpatient hospital charges for 695 000 hospital stays. The 1.1 million hospitalizations for CHF amounted to nearly $29 billion in hospital charges.69
In 2003, ≈48.3% of inpatient hospital stays for CVD were for women, who accounted for 42.8% of the national cost ($187 billion) associated with these conditions. Although only 40% of hospital stays for acute MI and coronary atherosclerosis were for women, more than half of all stays for nonspecific chest pain, CHF, and stroke were for women. There was no difference between men and women in hospitalizations for cardiac dysrhythmias.69
Circulatory disorders were the most frequent reason for admission to the hospital through the ED, accounting for 26.3% of all admissions through the ED. After pneumonia, the most common heart-related conditions (in descending order) were CHF, chest pain, hardening of the arteries, and heart attack, which together accounted for >15% of all admissions through the ED. Stroke and irregular heart beat ranked seventh and eighth, respectively.70
In 2004, nursing home residents had a primary diagnosis of CVD at admission (23.7%) and at the time of interview (25%). This was the leading primary diagnosis for these residents (NCHS, NNHS).67
Among current home health care patients in 2007, 18.3% had a primary diagnosis of CVD at admission and 62.9% had any diagnosis of CVD at the time of interview (NCHS, National Home and Hospice Care Survey [NHHCS] unpublished data).
Among patients discharged from hospice in 2007, 15.8% had a primary diagnosis of CVD at admission (NCHS, NHHCS unpublished data).
Operations and Procedures
In 2007, an estimated 6 846 000 inpatient cardiovascular operations and procedures were performed in the United States; 3.9 million were performed on males, and 2.9 million were performed on females (NHDS, NCHS, and NHLBI).
The estimated direct and indirect cost of CVD for 2007 is $286.6 billion (MEPS, AHRQ, and NHLBI).
In 2006, $32.7 billion in program payments were made to Medicare beneficiaries discharged from short-stay hospitals with a principal diagnosis of CVD. That was an average of $10 201 per discharge.71
- Pleis JR,
- Ward BW,
- Lucas JW
- Barnes PM,
- Adams PF,
- Powell-Griner E
National Institutes of HealthNational Heart, Lung, and Blood Institute. Incidence and Prevalence: 2006 Chart Book on Cardiovascular and Lung Diseases. Bethesda, Md: National Heart, Lung, and Blood Institute; 2006. Available at: http://www.nhlbi.nih.gov/resources/docs/06a_ip_chtbk.pdf. Accessed September 16, 2010.
- Schaefer C,
- Fabsitz RR
- Ali T,
- Jarvis B,
- O'Leary M
- Lloyd-Jones DM,
- Leip EP,
- Larson MG,
- D'Agostino RB,
- Beiser A,
- Wilson PW,
- Wolf PA,
- Levy D
- Xu J,
- Kochanek KD,
- Murphy S,
- Tejada-Vera B
National Center for Health Statistics. Health Data Interactive. Available at: http://www.cdc.gov/nchs/hdi.htm. Accessed July 12, 2010.
National Center for Health Statistics. HIST290A: deaths for selected causes by 10-year age groups, race, and sex: death registration states, 1900–32, and United States, 1933–98. Available at: http://www.cdc.gov/nchs/nvss/mortality/hist290a.htm. Accessed September 27, 2010.
National Center for Health Statistics. GMWK292F: deaths for 358 selected causes by 5-year age groups, race, and sex: United States, 1999–2007. Available at: http://www.cdc.gov/nchs/data/dvs/MortFinal2007_Worktable292F.pdf. Accessed November 2, 2010.
National Center for Health Statistics. Health, United States, 2009: With Special Feature on Medical Technology. Hyattsville, Md: National Center for Health Statistics; 2010. Available at: http://www.cdc.gov/nchs/data/hus/hus09.pdf. Accessed August 30, 2010.
- Anderson RN
- Danaei G,
- Ding EL,
- Mozaffarian D,
- Taylor B,
- Rhem J,
- Murray CJ,
- Ezzati M
- Jacobs I,
- Nadkarni V,
- Bahr J,
- Berg RA,
- Billi JE,
- Bossaert L,
- Cassan P,
- Coovadia A,
- D'Este K,
- Finn J,
- Halperin H,
- Handley A,
- Herlitz J,
- Hickey R,
- Idris A,
- Kloeck W,
- Larkin GL,
- Mancini ME,
- Mason P,
- Mears G,
- Monsieurs K,
- Montgomery W,
- Morley P,
- Nichol G,
- Nolan J,
- Okada K,
- Perlman J,
- Shuster M,
- Steen PA,
- Sterz F,
- Tibballs J,
- Timerman S,
- Truitt T,
- Zideman D
- Nichol G,
- Thomas E,
- Callaway CW,
- Hedges J,
- Powell JL,
- Aufderheide TP,
- Rea T,
- Lowe R,
- Brown T,
- Dreyer J,
- Davis D,
- Idris A,
- Stiell I
- Chugh SS,
- Jui J,
- Gunson K,
- Stecker EC,
- John BT,
- Thompson B,
- Ilias N,
- Vickers C,
- Dogra V,
- Daya M,
- Kron J,
- Zheng ZJ,
- Mensah G,
- McAnulty J
- Müller D,
- Agrawal R,
- Arntz HR
- Weisfeldt ML,
- Sitlani CM,
- Ornato JP,
- Rea T,
- Aufderheide TP,
- Davis D,
- Dreyer J,
- Hess EP,
- Jui J,
- Maloney J
- Valenzuela TD,
- Roe DJ,
- Cretin S,
- Spaite DW,
- Larsen MP
- Lloyd-Jones D,
- Adams R,
- Carnethon M,
- De Simone G,
- Ferguson TB,
- Flegal K,
- Ford E,
- Furie K,
- Go A,
- Greenlund K,
- Haase N,
- Hailpern S,
- Ho M,
- Howard V,
- Kissela B,
- Kittner S,
- Lackland D,
- Lisabeth L,
- Marelli A,
- McDermott M,
- Meigs J,
- Mozaffarian D,
- Nichol G,
- O'Donnell C,
- Roger V,
- Rosamond W,
- Sacco R,
- Sorlie P,
- Stafford R,
- Steinberger J,
- Thom T,
- Wasserthiel-Smoller S,
- Wong N,
- Wylie-Rosett J,
- Hong Y
- Galea S,
- Blaney S,
- Nandi A,
- Silverman R,
- Vlahov D,
- Foltin G,
- Kusick M,
- Tunik M,
- Richmond N
- Sasson C,
- Rogers MA,
- Dahl J,
- Kellermann AL
- Atkins DL,
- Everson-Stewart S,
- Sears GK,
- Daya M,
- Osmond MH,
- Warden CR,
- Berg RA
Annual Estimates of the Resident Population by Sex and Selected Age Groups for the United States: April 1, 2000 to July 1, 2009. US Census data. Available at: http://www.census.gov/popest/national/asrh/NC-EST2009-sa.html. Accessed November 2, 2010.
- Lotfi K,
- White L,
- Rea T,
- Cobb L,
- Copass M,
- Yin L,
- Becker L,
- Eisenberg M
- Maron BJ,
- Doerer JJ,
- Haas TS,
- Tierney DM,
- Mueller FO
- Mosca L,
- Mochari H,
- Christian A,
- Berra K,
- Taubert K,
- Mills T,
- Burdick KA,
- Simpson SL
- Vanhecke TE,
- Miller WM,
- Franklin BA,
- Weber JE,
- McCullough PA
- Stamler J,
- Stamler R,
- Neaton JD,
- Wentworth D,
- Daviglus ML,
- Garside D,
- Dyer AR,
- Liu K,
- Greenland P
- Mensah GA,
- Mokdad AH,
- Ford ES,
- Greenlund KJ,
- Croft JB
- Hozawa A,
- Folsom AR,
- Sharrett AR,
- Chambless LE
- Soni A
- Assmann G,
- Cullen P,
- Schulte H
- Parikh NI,
- Hwang SJ,
- Larson MG,
- Cupples LA,
- Fox CS,
- Manders ES,
- Murabito JM,
- Massaro JM,
- Hoffmann U,
- O'Donnell CJ
- Nasir K,
- Budoff MJ,
- Wong ND,
- Scheuner M,
- Herrington D,
- Arnett DK,
- Szklo M,
- Greenland P,
- Blumenthal RS
- Berry JD,
- Liu K,
- Folsom AR,
- Lewis CE,
- Carr JJ,
- Polak J,
- Shea SJ,
- Sidney S,
- O'Leary DH,
- Chan C,
- Lloyd-Jones DM
- Wright JD,
- Hirsch R,
- Wang CY
Centers for Disease Control and Prevention. National Center for Health Statistics. 2008 National Ambulatory Medical Care Survey. Unpublished data. For methodology, see National Center for Health Statistics. Public Use Data File Documentation: 2008 National Ambulatory Medical Care Survey, Hyattsville, Md, 2010. Available at: http://www.cdc.gov/nchs/ahcd/ahcd_questionnaires.htm. Accessed August 31, 2010.
Centers for Disease Control and Prevention. National Center for Health Statistics. 2008 National Hospital Ambulatory Medical Care Survey. Unpublished data. For methodology, see National Center for Health Statistics. Public Use Data File Documentation: 2008 National Hospital Ambulatory Medical Care Survey, Hyattsville, MD, 2010. Available at: http://www.cdc.gov/nchs/ahcd/ahcd_questionnaires.htm. Accessed August 31, 2010.
- Jones AL,
- Dwyer LL,
- Bercovitz AR,
- Strahan GW
- Russo CA,
- Andrews RM
- Elixhauser A,
- Jiang HJ
Centers for Medicare & Medicaid Services. Health Care Financing Review: Medicare & Medicaid Statistical Supplement. Table 5.5: Discharges, Total Days of Care, and Program Payments for Medicare Beneficiaries Discharged from Short-Stay Hospitals, by Principal Diagnoses Within Major Diagnostic Classifications (MDCs): Calendar Year 2006. Baltimore, Md: Centers for Medicare and Medicaid Services; 2005. Available at: http://www.cms.hhs.gov/MedicareMedicaidStatSupp/downloads/2007Table5.5b.pdf. Accessed September 27, 2010.
- D'Agostino RB Sr.,
- Vasan RS,
- Pencina MJ,
- Wolf PA,
- Cobain M,
- Massaro JM,
- Kannel WB
4. Subclinical Atherosclerosis
Atherosclerosis, a systemic disease process in which fatty deposits, inflammation, cells, and scar tissue build up within the walls of arteries, is the underlying cause of the majority of clinical cardiovascular events. Individuals who develop atherosclerosis tend to develop it in a number of different types of arteries (large and small arteries and those feeding the heart, brain, kidneys, and extremities), although they may have much more in some artery types than others. In recent decades, advances in imaging technology have allowed for improved ability to detect and quantify atherosclerosis at all stages and in multiple different vascular beds. Two modalities, computed tomography (CT) of the chest for evaluation of coronary artery calcification (CAC) and B-mode ultrasound of the neck for evaluation of carotid artery intima-media thickness (IMT), have been used in large studies with outcomes data and may help define the burden of atherosclerosis in individuals before they develop clinical events such as heart attack or stroke. Another commonly used method for detecting and quantifying atherosclerosis in the peripheral arteries is the ankle-brachial index, which is discussed in Chapter 10. Data on cardiovascular outcomes are starting to emerge for additional modalities for measuring subclinical disease, including brachial artery reactivity testing, aortic and carotid magnetic resonance imaging (MRI), and tonometric methods of measuring vascular compliance or microvascular reactivity. Further research may help to define the role of these techniques in cardiovascular risk assessment. Some guidelines have recommended screening for subclinical atherosclerosis, especially by CAC, or IMT may be appropriate in people at intermediate risk for heart disease (eg, 10-year estimated risk of 10% to 20%) but not for lower-risk general population screening or for people with preexisting HD, DM, or other high-risk conditions.1,2
Coronary Artery Calcification
CAC is a measure of the burden of atherosclerosis in the heart arteries and is measured by CT. Other parts of the atherosclerotic plaque, including fatty (eg, cholesterol-rich components) and fibrotic components, often accompany CAC and may be present even in the absence of CAC.
The presence of any CAC, which indicates that at least some atherosclerotic plaque is present, is defined by an Agatston score >0. Clinically significant plaque, frequently an indication for more aggressive risk factor management, is often defined by a score ≥100 or a score ≥75th percentile for one's age and sex. A score ≥400 has been noted to be an indication for further diagnostic evaluation (eg, exercise testing or myocardial perfusion imaging) for coronary artery disease (CAD).
The NHLBI's FHS measured CAC in 3238 white adults from <45 years of age to ≥75 years of age.3
Overall, 32.0% of women and 52.9% of men had prevalent CAC, defined as age-specific cut points >90th percentile in a healthy referent sample.
Among FHS participants at intermediate risk, 58% of women and 64% of men had prevalent CAC.
The NHLBI's Coronary Artery Risk Development in Young Adults (CARDIA) study measured CAC in 3043 black and white adults 33 to 45 years of age (at the CARDIA year 15 examination).4
— Overall, 15.0% of men and 5.1% of women, 5.5% of those 33 to 39 years of age and 13.3% of those 40 to 45 years of age, had prevalent CAC. Overall, 1.6% of subjects had a score that exceeded 100.
— Chart 4-1 shows the prevalence of CAC by ethnicity and sex. The prevalence of CAC was lower in black men than in white men but was similar in black and white women at these ages.
The NHLBI's MESA study measured CAC in 6814 subjects 45 to 84 years of age, including white (n=2619), black (n=1898), Hispanic (n=1494), and Chinese (n=803) men and women.5
— Chart 4-2 shows the prevalence of CAC by sex and ethnicity.
— The prevalence and 75th percentile levels of CAC were highest in white men and lowest in black and Hispanic women. Significant ethnic differences persisted after adjustment for risk factors, with the RR of coronary calcium being 22% less in blacks, 15% less in Hispanics, and 8% less in Chinese than in whites.
— Table 4-1 shows the 75th percentile levels of CAC by sex and race at selected ages. These might be considered cut points above which more aggressive efforts to control risk factors (eg, elevated cholesterol or BP) could be implemented and/or at which treatment goals might be more aggressive (eg, LDL cholesterol <100 mg/dL instead of <130 mg/dL).
CAC and Incidence of Coronary Events
The NHLBI's MESA study recently reported on the association of CAC scores with first CHD events over a median follow-up of 3.9 years among a population-based sample of 6722 men and women (39% white, 27% black, 22% Hispanic, and 12% Chinese).6
— Chart 4-3 shows the relative risks (RRs) or hazard ratios (HRs) associated with CAC scores of 1 to 100, 101 to 300, and >300 compared with those without CAC (score=0), after adjustment for standard risk factors. People with CAC scores of 1 to 100 had ≈4 times greater risk and those with CAC scores >100 were 7 to 10 times more likely to experience a coronary event than those without CAC.
— CAC provided similar predictive value for coronary events in whites, Chinese, blacks, and Hispanics (HRs ranging from 1.15 to 1.39 for each doubling of coronary calcium).
In another report of a community-based sample, not referred for clinical reasons, the South Bay Heart Watch examined CAC in 1461 adults (average age 66 years) with coronary risk factors, with a median of 7.0 years of follow-up.7
Chart 4-4 shows the HRs associated with increasing CAC scores (relative to CAC=0 and <10% risk category) in low-risk (<10%), intermediate-risk (10% to 15% and 16% to 20%), and high-risk (>20%) Framingham Risk Score (FRS) categories of estimated risk for CHD in 10 years. Increasing CAC scores further predicted risk in intermediate- and high-risk groups.
In a study of healthy adults 60 to 72 years of age who were free of clinical CAD, predictors of the progression of CAC were assessed. Predictors tested included age, sex, race/ethnicity, smoking status, BMI, family history of CAD, C-reactive protein, several measures of DM, insulin levels, BP, and lipids. Insulin resistance, in addition to the traditional cardiac risk factors, independently predicts progression of CAC.8 Clinically, however, it is not yet recommended to conduct serial scanning of CAC to measure effects of therapeutic interventions.
It is noteworthy that, as recently demonstrated in the MESA study in 5878 subjects with a median of 5.8 years of follow-up, the addition of CAC to standard risk factors resulted in significant improvement of classification of risk for incident CHD events, placing 77% of people in the highest or lowest risk categories compared with 69% based on risk factors alone. Moreover, an additional 23% of those who experienced events were reclassified as high risk and 13% with events were reclassified as low risk.9
Carotid IMT measures the thickness of 2 layers (the intima and media) of the wall of the carotid arteries, the largest conduits of blood going to the brain. Carotid IMT is thought to be an even earlier manifestation of atherosclerosis than CAC, because thickening precedes the development of frank atherosclerotic plaque. Carotid IMT methods are still being refined, so it is important to know which part of the artery was measured (common carotid, internal carotid, or bulb) and whether near and far walls were both measured. This information can affect the average-thickness measurement that is usually reported.
Unlike CAC, everyone has some thickness to their arteries, but people who develop atherosclerosis have greater thickness. Ultrasound of the carotid arteries can also detect plaques and determine the degree of narrowing of the artery that they may cause. Epidemiological data, including the data discussed below, have indicated that high-risk levels might be considered as those in the highest quartile or quintile for one's age and sex, or ≥1 mm.
Although ultrasound is commonly used to diagnose plaque in the carotid arteries in people who have had strokes or who have bruits (sounds of turbulence in the artery), guidelines are limited as to screening of asymptomatic people for carotid IMT to quantify atherosclerosis or predict risk. However, some organizations have recognized that caroti