Coronary Heart Disease, Stroke Death Rates Take
Significant 30 Percent Drop from 1999
Cholesterol down for older people, progress lags in
fighting obesity, diabetes, physical inactivity
Dec. 17, 2008 – Death rates for coronary disease
and stroke have dropped about 30 percent since 1999, although obesity,
diabetes and physical inactivity are still growing risk factors,
according to Heart Disease and Stroke Statistics – 2009 Update by the
American Heart Association. A major risk that has been in the spotlight
in recent years - total cholesterol levels – has declined for women 60
and older and men over 39.
The total cholesterol levels for these older
Americans declined from 204 mg/dL to 199 mg/dL. However, there was
little change over this time period for other age groups
The age-adjusted death rates for coronary heart
disease and stroke have each reached about a 30 percent reduction since
1999, according to the latest data in the American Heart Association’s
Heart Disease and Stroke Statistics – 2009 Update,
The age-adjusted reductions in the coronary heart
disease (30.7 percent) and stroke (29.2 percent) death rates mark the
achievement of major milestones set by the American Heart Association to
reduce coronary heart disease and stroke by 25 percent by 2010. The
results are published online in Circulation: Journal of the American
Heart Association.
This latest preliminary data for 2006, the most
recent year for which statistics are available, reflects further
reductions from the 2005 numbers announced earlier in 2008.
“The American Heart Association is proud of the
progress this country has made against America’s No. 1 single cause of
death and the No. 3 killer,” said association president Timothy Gardner,
M.D.
“There has been a tremendous effort from many
partners in research, healthcare, government, business and communities
to achieve these goals,” Gardner said.
“But our work is not done, since the major risk
factors for heart disease and stroke have not seen the same decline as
the death rates – and several are rising.
“If this trend continues, death rates could begin
to rise again in the years ahead. While we have seen better control of
high blood pressure, high cholesterol and tobacco use, we still have
much work to do on these risk factors – and progress continues to lag in
obesity, diabetes and physical inactivity.”
While the death rates for heart disease and stroke
have declined, the burden of disease is still high for the nation’s
leading killer, and many risk factors for cardiovascular disease (CVD)
are either unchanged or increasing.
• Preliminary mortality data for 2006 show that CVD
accounted for 34.2 percent (829,072) of all 2,425,901 deaths in 2006, or
1 of every 2.9 deaths in the United States.
• Cholesterol: Between 1999–2000 and 2005–2006,
average total cholesterol levels for men age 40 or older and for women
age 60 or older declined from 204 mg/dL to 199 mg/dL. However, there was
little change over this time period for other age groups.
• Physical Activity: Despite recommendations that
some proportion of activity be vigorous (activity that causes heavy
sweating and a large increase in breathing and/or heart rate), 62
percent of adults (age 18 and up) who responded to the 2006 National
Health Interview Survey reported no vigorous activity lasting at least
10 minutes per session.
• Overweight: The presence of overweight (body mass
index-for-age values at or above the 95th percentile) in children age 6
to 11 years old increased from 4.0 percent in 1971–1974 to 17.0 percent
in 2003–2006.
> In adolescents aged 12 to 19 it increased from 6.1 percent to
17.6 percent in that same time frame.
> Among infants and children between the ages of 6 months and 23
months, the prevalence of high weight-for-age was 7.2 percent in
1976–1980 and 11.5 percent in 2003–2006.
“The challenge we face with reducing risk factors
is figuring out what motivates people to change behavior, narrowing the
gaps in gender and socioeconomic disparities, and assessing what we can
do on a broad scale to affect the environments where people live, work
and play,” Gardner said.
Coronary Artery Calcification (CAC)
For the first time, the annual update includes data
on the early stages of CVD as measured by coronary artery calcification
(CAC) scores and carotid intima-media thickness (IMT). A CAC score is
measured using ultrafast computed tomography to detect calcified
deposits in the walls of coronary heart arteries. Carotid IMT uses
B-mode ultrasound to measure the thickness of neck arteries. Both
measure the early manifestations of atherosclerosis and have been used
to foretell a person’s risk for heart attack and stroke.
“Perhaps expanding our knowledge on how early the
disease process begins can help people take action earlier in life, when
prevention really counts,” said Don Lloyd-Jones, M.D., Sc.M., chair of
the American Heart Association Statistics Committee and the lead author
of the update.
“Advances in imaging technology over the past
several decades have made it possible to take a closer look at blood
vessels, so we can see the changes that eventually lead to widespread
disease, heart attack or stroke,” he said.
For example, the National Heart, Lung, and Blood
Institute’s Coronary Artery Risk Development in Young Adults (CARDIA)
study and Multi-Ethnic Study of Atherosclerosis (MESA) have helped to
define levels of CAC in a diverse population.
• In adults 33 to 45 years of age in CARDIA, 15
percent of men and 5.1 percent of women already had CAC, and 1.6 percent
had a CAC score higher than 100, which may indicate a significant burden
of plaque.
• Among older adults in MESA, levels of CAC were
highest in white men and lowest in black and Hispanic women.
• According to longitudinal data from MESA, older
people with CAC scores of one to 100 were about four times more likely
and those with CAC scores greater than 100 were seven to 10 times more
likely to suffer a coronary event than those without CAC.
Carotid IMT, without obvious atherosclerotic
plaque, is thought to represent an even earlier sign of atherosclerosis
than CAC. Analyses from the Bogalusa Heart Study, CARDIA, MESA, and the
Cardiovascular Health Study have helped to describe the relationship of
carotid IMT to CVD risk, and show that higher body mass index and
low-density lipoprotein cholesterol levels measured at four to 17 years
of age were associated with increased risk for being above the 75th
percentile for carotid IMT later on young adulthood.
“These data highlight the importance of controlling
risk factor levels and obesity in early childhood and young adulthood to
prevent the early development of atherosclerosis,” Lloyd-Jones said.
Other highlights from this year’s statistical
update include:
• A new section highlighting the complex
association between family history of CVD and future risk for CVD among
offspring and siblings;
• A revised chapter on congenital cardiovascular
disease;
• Substantial revisions and updates to the chapter
describing current nutritional intake data, trends and changes in
intakes, estimated effects on cardiovascular risk factors and
cardiovascular outcomes, and current costs and trends for all foods; and
• New data on quality of care performance measures
stratified by race/ethnicity and sex for hospitals participating in the
American Heart Association’s Get With The Guidelines program from
January 1, 2007, through December 31, 2007.
Note: Age Adjusted?
Comparisons cannot be done on raw, or crude,
numbers of deaths because the populations may not be comparable with
respect to age. Much like finding the common denominator when working
with fractions, epidemiologists must calculate age-adjusted incidence or
death rates so that different population groups are similar enough for
comparison.
