About one in 35 adult Americans is at high risk of coronary heart disease, meaning they have a greater than 20 percent chance of developing heart disease within 10 years, and about one in six has a 10-year risk that is greater than 10 percent, according to a new study
in the May 19, 2004 issue of the Journal of the American College of Cardiology
"I hope that these numbers will give clinicians, researchers, health policy analysts, and others a better idea of how coronary heart disease is distributed in the U.S. population," said Earl S. Ford, MD, MPH with the Centers for Disease Control and Prevention in Atlanta.
The researchers developed risk predictions for people who, based on self-reports, were free of coronary heart disease, such as heart attack and angina pectoris, or signs of stroke, peripheral vascular disease, or diabetes. They used data on the prevalence of heart disease risk factors among Americans age 20 to 79 years collected by the CDC as part of the Third National Health and Nutrition Examination Survey (http://www.cdc.gov/nchs/nhanes.htm), which ran from 1988 to 1994. The data include cholesterol levels, blood pressure, age, body mass index, smoking, and other factors.
"It's a nice data set. It's probably the most representative data of the United States population. It includes a cross-section of Americans and samples them throughout the country. It includes sizeable numbers of minorities, men and women, and all age groups," Dr. Ford said.
The researchers calculated heart disease risk using a formula based on guidelines from the National Cholesterol Education Program Adult Treatment Panel III (http://www.nhlbi.nih.gov/guidelines/cholesterol/) which help clinicians predict the likelihood that an individual patient will develop heart disease based on risk factor measurements.
Among those without heart disease or heart disease equivalents (such as stroke, peripheral vascular disease or diabetes) 2.9 percent were in the high-risk category, meaning they had a greater than 20 percent of developing heart disease within 10 years. An estimated 15.5 percent fell into the intermediate risk category (10 to 20 percent risk of developing heart disease within a decade); while 81.7 percent had a 10-year risk of developing heart disease of less than 10 percent.
Dr. Ford noted that these estimates are predictions of future risk based on the best available models and data, not measurements of how many people actually developed heart disease over a 10-year period. He said this broad picture of heart disease risk may be useful to policymakers who develop recommendations for prevention programs or treatment, economists who calculate future health care consumption, and others who track heart disease.
"It gives a broad view of this risk in the U.S. population. It may also allow comparisons with other countries," Dr. Ford said.
In an editorial in the journal, Daniel S. Berman, MD, FACC from Cedars-Sinai Medical Center, in Los Angeles, and Nathan D. Wong, PhD, FACC from the University of California at Irvine, wrote that the impending heart disease risk depicted in the calculations suggests a call to action to identify and intervene with individual patients.
"For example, in many of these persons, LDL-cholesterol should be reduced to below 100 milligrams/deciliter, particularly if coronary heart disease or diabetes is already present, but also for those with multiple risk factors who have an estimated risk of coronary heart disease of greater than 20 percent in the next 10 years. For those at intermediate risk, 10 to 20 percent, current guidelines recommend the possible use of non-invasive imaging tests (such as coronary calcium screening, carotid ultrasound, or the ankle-brachial index) to aid in detecting early atherosclerosis, which if present to a significant degree, may warrant risk stratification to the highest risk category warranting aggressive risk factor intervention as a coronary heart disease risk equivalent," Dr. Wong said.
The authors of the editorial also said the nation should take further public health and preventive measures to reduce risk factors for heart disease.
The American College of Cardiology, a 29,000-member nonprofit professional medical society and teaching institution, is dedicated to fostering optimal cardiovascular care and disease prevention through professional education, promotion of research, leadership in the development of standards and guidelines, and the formulation of health care policy. http://www.acc.org