Heart attack, which is the end result of coronary heart disease (CHD), is the single largest killer of American males and females.
The CDC report, an analysis of CHD deaths in each of the United States from 1990 to 1994, concluded that the age-adjusted rate of decline in CHD deaths -- which began to drop in the 1960s -- has begun to slow. The average annual decline in the age-adjusted death rate during this decade has been 2.6 percent, compared to 3 percent in the 1980s.
"People are having heart attacks later and more people are surviving their first attacks," said Breslow. "This results in heart attack deaths being shifted to older ages and the lowering of the age-adjusted death rate. And, unfortunately, this rate is slowing."
The age-adjusted death rate, which is used by the government, is based on the number of people in the U.S. population in 1940 and is designed to eliminate the effect of population growth over the years. While the age-adjusted death rate has declined since the 1960s, it is estimated that the prevalence of CHD has increased 2 to 3 fold in the last 15 years, said Breslow.
The CDC report does not identify actual or possible factors responsible for the slowdown in the decline in the age-adjusted death rate from CHD, the major form of heart disease. "The American Heart Association also cannot explain all the reasons for what may be a stalling of the decline in the age-adjusted death rate," said Breslow, a senior professor at Rockefeller University in New York City. "But, we do know that despite public health education campaigns, the population is becoming more obese and physically inactive and that alarming numbers of our adolescents and teenagers are still smoking.
"The slowdown in the decline of CHD deaths is ominous," said Breslow, "because combined with the trends in obesity, physical inactivity, and smoking, it may mean that people will be suffering and dying from heart disease in great numbers for too many decades into the 21st century."
Obesity, physical inactivity, cigarette smoking, as well as high blood cholesterol, hypertension and diabetes are risk factors for heart disease and stroke. These diseases can strike a person at any age, from childhood on, Breslow pointed out, adding that 6.7 million of the 13.7 heart attack survivors living today in the U.S. are under 60.
The American Heart Association estimates that CHD alone will cost the nation $90.9 billion in 1997. "These dollars do not tell the whole story of how heart disease impairs the lives of individual people," Breslow said. Almost one-half million Americans die annually from CHD. Heart attack can be effectively treated in many victims through clot-busting drugs and other means. "But many survivors of heart attack are disabled," he noted.
"Coronary heart disease is becoming a worldwide problem," added Breslow, explaining that the World Health Organization has predicted that CHD will replace pneumonia as the world's Number One disease burden by 2020.
Breslow said that the American Heart Association supports the CDC's call for more attention to prevention through a "heart-healthy" diet, increased physical activity opportunities, cigarette smoking prevention and cessation, and medical care to prevent and control hypertension, diabetes and high blood cholesterol.
However, risk factors modification is not a cure -- for many people, it simply delays onset of the disease, stressed Breslow. If heart disease is to be cured, scientists need to know more about how the CHD process begins and progresses at the level of the cells lining the blood vessels feeding the heart. Changes in these cells create the obstructions that choke the blood supply to the heart -- and that instigate a heart attack.
The origin of CHD at the cellular level was among the 14 areas of research identified by the American Heart Association's scientific councils as important to advancing the prevention and treatment of heart disease and stroke.
According to the 1997 Heart and Stroke Statistical Update, published last month by the American Heart Association, this year as many as 1,500,000 Americans will have a new or recurrent heart attack. About one third of them will die. The update also reports:
- Heart attacks kill at least 250,000 people a year within one hour of the onset of symptoms such as chest pain and before they reach a hospital. An estimated 48 percent of men and 63 percent of women who die suddenly of heart attack had no previous symptoms.
- 13,670,000 people alive today have a history of heart attack, chest pain or both.
- About 45 percent of all heart attacks occur in people younger than 65.
- People who survive the acute stage of a heart attack have a
2-to-9-times-greater chance of illness and death. The survivors are at higher
risk of heart attack, sudden death, angina chest pain, heart failure and stroke
than they were before their attack.
· About two-thirds of heart-attack patients don't make a complete recovery, and within six years after a heart attack, 23 percent of men and 31 percent of women will have another heart attack.