NEW ORLEANS — Sisters of patients with early coronary disease had an unexpectedly high prevalence of coronary artery disease themselves in a study with 102 apparently healthy women without diabetes.
The actual presence of coronary disease in these women far exceeded their estimated risk calculated by the Framingham risk formula, the major tool used in the United States to assess a person's 10-year risk of having a major coronary event. Because of this disparity between estimated risk and actual disease in women with a family history of coronary disease, such women “likely warrant being considered for noninvasive screening for subclinical atherosclerosis,” Erin D. Michos, M.D., said at the annual scientific sessions of the American Heart Association.
The noninvasive screening could consist of measuring the woman's serum level of C-reactive protein, or measuring coronary calcium with CT, said Roger S. Blumenthal, M.D., director of preventive cardiology at Johns Hopkins Hospital in Baltimore and a coinvestigator in the study.
The 102 women in the study were sisters of 71 probands who had been identified with coronary artery disease when they were younger than 60 years. The coronary-disease risk of each woman was calculated using the Framingham risk score, and each woman also had her coronary calcium measured by multidetector CT. The Framingham scoring system estimates a person's risk for having a coronary disease event by using several clinical variables, such as blood pressure and total serum cholesterol level, but the score does not take into account a person's family history of coronary disease.
The average Framingham risk score for the entire group was a 2% risk for a major coronary event over the next 10 years. Broken down, 95 women (93%) had a very low Framingham risk score of 5% or less, and another 5 (5%) had a low risk score of 6%–9.9%. Only two women (2%) had intermediate-risk scores of 10%–19.9%, and none had high-risk scores of 20% or greater, said Dr. Michos of the Preventive Cardiology Center at Johns Hopkins Hospital.
Despite these very low Framingham scores, many women had significant amounts of coronary calcium. Twelve women (12%) had coronary calcium scores that were greater than 100, an indicator of moderate atherosclerosis; 9 of the women with these relatively high levels of coronary calcium had Framingham scores of 5% or less. Of the 12 women with calcium scores of greater than 100, 6 had calcium scores that were greater than 400, a marker of severe atherosclerosis.
In addition, of the women with Framingham scores of 5% or less, 28 (29%) had calcium scores that were above the 75th percentile for similarly aged women.