DALLAS, Jan. 1 -- Following the federal government's lead, the American Heart Association has updated the way it computes age-adjusted death rates from heart attack and stroke, resulting in death rates that scientists say more realistically depict the true burden of cardiovascular disease, this nation's No. 1 killer.
The new death rates are published in the AHA's 1999 Heart and Stroke Statistical Update, an annual report about statistics on cardiovascular disease that was released today.
According to AHA's President Valentin Fuster, M.D., Ph.D., "The good news is that the new year brings a new formula for compiling death rates for cardiovascular disease that the AHA welcomes. The bad news is that it only reinforces how immense the burden of heart disease and stroke is on the public."
To describe heart disease and stroke trends, health officials calculate statistics such as number of deaths, or mortality, and death rates. The death rate is obtained by dividing the number of cardiovascular disease deaths by the United States population. But because heart disease and stroke deaths increase dramatically at older ages, the death rates need to be adjusted for the aging of the U.S. population so they don't simply reflect the effect of an increasing number of older persons over time.
Age-adjustment allows a comparison of death rates by race, sex and geographic location, without the influence of differences in how much older one population group is than another. Age-adjustment works like a currency so that different populations can be compared, or the same populations can be compared, over time to determine trends in diseases.
The new age-adjusted death rates are adjusted to the age-distribution (number of individuals in each 10 year grouping) of the U.S. population in the year 2000 replacing the old standard that was based on the age-distribution of the 1940 population.
The U.S. population projected for the year 2000 has many more older people than the 1940 population did. As a result, heart disease and stroke death rates adjusted to year 2000 are much higher than those adjusted to 1940 standard. The death rate from coronary heart disease, the cause of heart attack, was 187.1 people per 100,000 in 1996, according to the new death rate calculations. The "old" calculation using the 1940 population was 86.7 deaths per 100,000. The rate of stroke was 63.2 per 100,000 based on the population of 2000 versus 26.4 per 100,000 based on the "old" calculation using the 1940 population. For total cardiovascular disease, the new rate was 377.3 per 100,000 versus the 1940 rate of 173.5
"Compared to 1940, the population of the year 2000 will include almost twice as many individuals 65 years and older, an age range when heart attack and stroke are more likely to occur. Therefore it may seem as if death rates have jumped," says Fuster.
"We do not suddenly have a new epidemic -- the number of deaths from cardiovascular disease has not suddenly doubled in the last year. However, the number of deaths has been gradually increasing as the percentage of individuals over age 65 has increased. The increase in the number of senior citizens means more Americans are dying from heart attack and stroke than has been reflected in the 1940-based statistics," he says.
"The new death rates standard paints a more realistic picture of the mortality from heart disease and stroke, one that should make everyone more aware of the importance of stepping up the battle against cardiovascular disease, which takes a life every 33 seconds," says Fuster, director of the Cardiovascular Institute, Mount Sinai Medical Center, New York.
AHA Releases New Data on Smoking and Other Risk Factors
The American Heart Association's 1999 Heart and Stroke Statistical Update is
among the first to publish information that will reflect new age-adjusted death
rates from cardiovascular disease. The new edition lists age-adjusted rates for
both the 1940 and 2000 populations. The new edition also updates statistics on
death and prevalence of cardiovascular disease -- as well as data on risk
factors such as elevated blood cholesterol, smoking and high blood pressure.
"These statistics on risk factors show that there are still major problems in how people -- especially women -- perceive heart disease and its threat to their lives. Heart disease and stroke are largely preventable diseases but large numbers of individuals may still not be listening or complying with the advice to improve their lifestyles, stop smoking, exercise more and watch their diets," Fuster says.
"New data on cigarette smoking, blood cholesterol and physical activity are alarming. Nearly one in five cardiovascular disease deaths is attributable to smoking -- and studies show that 43 percent of American children are exposed to environmental tobacco smoke in the home," says Fuster.
In addition, more than half of all American adults have above-average total blood cholesterol -- 200 milligrams per deciliter (mg/dl) or higher -- and about 20 percent have "elevated" levels -- 240 mg/dL or above. Women over 50 are more likely to have higher total blood cholesterol than men. Elevated LDL and total cholesterol increase the risk of atherosclerosis, the main cause of heart attacks and strokes.
More than 49 million Americans -- about 25 percent who are 18 or older -- report no leisure-time activity. "Once again we find that among women, physical inactivity is more prevalent that it is in men," says Fuster. He adds that inactivity doubles the risk of heart disease, putting it on equal footing to that of high blood pressure, high blood cholesterol and cigarette smoking."
Other New Facts About Cardiovascular Disease
- 58,800,000 Americans have one or more types of cardiovascular disease.
- 50,000,000 Americans have high blood pressure.
- 1 in 5 males and females has some form of cardiovascular disease.
- 959,227 deaths were caused by cardiovascular disease in 1996.
- More than 2,600 Americans die each day of cardiovascular disease -- an average
of one death every 33 seconds.
- Stroke killed 159,942 people in 1996 -- on average a stroke death occurs every
3.3 minutes.
- Stroke is a leading cause of serious, long-term disability that accounts for
more than half of all patients hospitalized for neurological disease, and stroke
deaths have been increasing in recent years.
- About 400,000 new cases of congestive heart failure occur each year.
Congestive heart failure deaths continue to increase dramatically.
- In 1996 an estimated 598,000 coronary artery bypass surgeries and 482,000
coronary angioplasties (both procedures to restore blood flow in the heart) were
performed
- The cost of cardiovascular disease in 1999 is estimated at $286.5 billion -- an increase of about $12 billion from last year.