The National Heart, Lung, and Blood Institute (NHLBI) has launched a 10-year, multicenter study to find new ways of detecting heart disease early, before it produces symptoms.
The $68 million Multi-Ethnic Study of Atherosclerosis (MESA) will involve six centers, which will recruit 6,500 participants aged 45 to 84. Half of the participants will be men and half women. About 40 percent of the participants will be white, 30 percent African American, 20 percent Hispanic, and 10 percent Asian, mostly of Chinese ancestry. None of the participants will have known heart disease at the time of their enrollment in the study.
The six centers are: Columbia University in New York City, The Johns Hopkins University in Baltimore, MD, Northwestern University in Chicago, IL, the University of Minnesota in Minneapolis-St. Paul, the University of California at Los Angeles, and Wake Forest University in Winston-Salem, NC. The study's coordinating center is the University of Washington in Seattle.
"The earlier the risk of heart disease can be detected, the sooner steps can be taken to prevent its development," said NHLBI Director Dr. Claude Lenfant. "Most of this prevention effort has focused on the standard risk factors for heart disease. This study may give us new and better indicators of heart disease risk."
The study also could yield more specific predictors of heart disease: It will try to determine which factors best predict heart disease in men and women, and in each of the ethnic groups.
"The progression of heart disease from being subclinical, or without signs or symptoms, to clinical has not really been studied before in some groups, such as Asians," said Dr. Robin Boineau, NHLBI Deputy Project Officer for MESA. "All of the participants will be undergoing the same tests and it will be possible to see differences in how the disease develops."
Standard risk factors for heart disease are high blood pressure, high blood cholesterol, cigarette smoking, diabetes, overweight, physical inactivity, age (45 or older for men; 55 or older for women), and family history of early heart disease (a father or brother diagnosed with heart disease before age 55, or a mother or sister diagnosed before age 65).
The study will collect information on those risk factors, as well as other sociodemographic, lifestyle, and psychosocial factors. It also will examine a variety of newly emerging factors, such as calcium deposits in the coronary artery. These deposits have been correlated with an increased risk of coronary artery disease. However it is not known if such deposits can pinpoint who will actually develop the disease.
"This study will use computed tomography, a device which gives cross-sectional images of the heart. The images will be checked for the amount of calcium in the coronary arteries to see if that predicts who goes on to develop coronary artery disease," said Boineau.
Other tests to be undertaken include: cardiac magnetic resonance imaging (MRI), a noninvasive device that gives images of the heart, including its mass; ultrasound, a noninvasive device that measures the thickness and flexibility of the carotid artery wall; ankle-brachial blood pressure index, which assesses the blood flow in the lower extremities; electrocardiogram; blood samples to measure new risk factors such as indicators of inflammation and genetic markers; and a device that measures pulse waves at the artery.
"Some of these tests could be easily done in the doctor's office, if they prove to be effective predictors of heart disease. For example, the device that measures the pulse waves at radial artery of the wrist could be used during a routine checkup," explained Boineau.
Participants will undergo four examinations over the course of the study. Besides coronary artery disease, they will be followed to see if certain factors can predict the development of stroke and congestive heart failure.
To interview Dr. Boineau or Dr. Diane Bild, NHLBI Project Officer for MESA, please contact the NHLBI Communications Office at (301) 496-4236.
NHLBI press releases and other materials are online at www.nhlbi.nih.gov.