Heart, Stroke Death Rates Down
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, published online in Circulation: Journal of the American Heart Association.
The 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. 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.
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.