Women with coronary calcium found at risk for heart attack

Women who have scan-detected coronary artery calcium might have a greater risk of heart and vascular trouble than their Framingham risk scores indicate, according to a study published in the Dec. 10/24, 2007, Archives of Internal Medicine.

"Framingham is our best risk score right now, but this study challenges us to do a better job of assessing risk in women and identifying who is going to have an event," said Susan G. Lakoski, MD, lead author and a fellow at North Carolina's Wake Forest University School of Medicine.

Researchers analyzed data on 3,601 women followed for nearly four years. Approximately 90% were identified by Framingham as not having much of a chance of developing heart problems. But of this group, 32% had calcium deposits in their coronary arteries, which actually increased the odds of developing coronary heart disease during the study period to 6.5-to-1.

Assessment works better for men

The paper is the most recent to suggest that Framingham does not work as well for women as it does for men.

The vast majority of females are classified as low risk for heart disease according to Framingham. This categorization means they are not candidates for aggressive primary prevention despite the fact that the majority will die of cardiovascular-related conditions. And those behind Framingham agree it may be time for a revision, to take into account not just new technology but more traditional factors that can impact women.

"These risk scores definitely need to be updated, particularly to work family history into the algorithm as well as newer assessment modalities," said Christopher O'Donnell, MD, MPH, associate director of the National Heart, Lung and Blood Institute's Framingham Heart Study. He wrote the accompanying editorial. "It has been 10 years since it was last revised, and it does warrant being revised from time to time."

But while many experts said the study was interesting, they, along with the authors, also said it does not indicate how coronary calcium measurements should be used.

"Future studies need to verify the results and that this is a cost-effective strategy," said Dr. Lakoski. "Coronary calcium is predictive, but it would be premature to say scan everyone."

The test is used by many physicians to varying degrees, although the most recent guidelines on preventing cardiovascular disease in women from the American Heart Assn. noted that its role in risk stratification is unclear.

Many experts also maintain that the evidence, including that advanced in the study, is not compelling enough to endorse wider use. Additionally, the study found that coronary artery calcium is associated with an increased risk of heart disease, but did not prove that measuring it could improve outcomes.

"We encourage doctors to take it into consideration if it gets done. It can help to identify who might need more aggressive preventive therapy. But we need more research to assess the clinical utility of this. We don't know that acting on this information is for the benefit of the patient," said Lori Mosca, MD, MPH, PhD, lead author on the AHA guidelines and director of preventive cardiology at New York-Presbyterian Hospital.

Physicians are concerned that exposing many women to the small amount of radiation involved in the test might not be worth the procedure's associated risks. Women also may be subject to unnecessary follow-up testing for ancillary findings.

"Framingham may not be so great in women, but I'm not sure if doing a coronary calcium score on every woman is the answer," said Leslie Cho, MD, director of the Women's Cardiovascular Center at the Cleveland Clinic.

While understanding of the cardiovascular health differences between the genders is growing, another paper in the same journal posed questions about how clinically relevant the variations may be. For example, several studies have documented that, although chest pain is the most common sign of a heart attack overall, women are more likely to present with symptoms, such as nausea or vomiting, not considered typical. A review of the literature suggested these differences were not common enough to call for sex-specific public health messages.