Some 5% of women rated as low-risk for heart disease show indications of advanced coronary artery calcium, and may be at risk for cardiovascular problems, according to a report in Archives of Internal Medicine.
The standard method for assessing a person’s risk of developing coronary heart disease in the next 10 years is the Framingham risk score, which measures age, cholesterol and blood pressure levels, smoking habits and diabetes. Americans are considered low-risk if their risk is estimated at less than 10% in 10 years, and high risk if the risk is 20% or more in 10 years.
Approximately 95% of American women aged less than 70 are considered low-risk. “Nevertheless”, write the authors, “most women will ultimately die of heart disease, suggesting that the Framingham risk score alone does not adequately identify women in ways that would be useful for targeted preventive interventions”.
Susna G. Lakoski, M.D., M.S., of the Wake Forest School of Medicine, Winston-Salem, N.C., and colleagues measured 3,601 women aged 45 to 84, in 2000. Computed tomographic (CT) chest scans determined scores for coronary artery calcium. High scores pointed to considerable amounts of calcium deposits. Participants were interviewed by telephone every 9 to 12 months about any subsequent cardiovascular diagnoses and hospital admissions.
2,684 (90%) of women were assessed as low-risk by the Framingham score. 32% had detectable calcium in their coronary arteries, while during an average of 3.75 years, 24 of the low-risk women had heart attacks or heart pain, and 34% had a cardiovascular disease event such as heart attacks, stroke or death.
“Compared with women with no detectable coronary artery calcium, low-risk women with a coronary artery calcium score greater than zero were at increased risk for coronary heart disease and cardiovascular disease events,” the authors write. In addition, almost 5 percent of the low-risk women had advanced coronary artery calcium, defined as a score of 300 or greater. These women had a 6.7 percent risk of a heart event and 8.6 percent risk of a cardiovascular event over the 3.75-year follow-up.
The authors believe that these data provide new information on cardiovascular disease risk and the evaluation and treatment of it in middle-aged and older women. They also maintain that women with coronary artery calcium are at potentially higher risk that A Framingham risk score would suggest. Further studies with longer follow-up periods will be required to determine whether women should be screened for coronary artery calcium, or treated more aggressively for heart disease risk factors.
Source: Arch Intern Med. 2007;167(22):2399-2401