Heart disease risk tool fails in women

A commonly used method for assessing heart disease risk appears to underestimate women's risk for significant atherosclerosis (hardening of the arteries) when they have a family history of early heart disease, investigators at Johns Hopkins Medical Institutions report.

Study chief Dr. Roger S. Blumenthal told Reuters Health, because the so-called Framingham risk estimation or "FRE" weighs age so strongly and doesn't take into account family history or increased waist circumferences or lack of exercise, "we think that it misses a lot of women who should be more aggressively treated with medication and lifestyle changes."

The Baltimore-based research team used CT scanning to check for a build-up of calcium deposits on artery walls, an early sign of atherosclerosis, in 102 women ages 30 to 59 years who had siblings with coronary heart disease occurring before age 60.

Only two of the subjects had FRE scores indicating an intermediate risk of having a cardiovascular event - that is, a 10 percent to 19 percent risk over 10 years.

However, 32 percent had significant silent or "subclinical" atherosclerosis, with high coronary artery calcium scores above the 75th percentile for their age and gender, the team reports in the American Heart Journal.

In terms of actual coronary artery calcium scores, 12 percent had a score above 100, indicating moderately high heart disease risk; and 6 percent had scores above 400, indicating extensive hardening of the arteries.

"These women almost surely should be on aspirin and cholesterol lowering therapy," Blumenthal said. "If we relied only on FRE we would miss them."

He recommends for patients with a family history of premature heart disease that their physician either incorporate imaging studies, such as cardiac CT, or measure blood levels of CRP, a marker of inflammation, along with standard blood work for blood sugar and lipids.

The additional advantage of an imaging study, he pointed out, is that "you have more ammunition to help motivate them to exercise more days/week and more vigorously, improve their diet and accept a more aggressive medical regimen."

"Our hope," he added, "is that investigators will update FRE to incorporate family history, since we now know that for these patients the risk is double what the current equation predicts."

SOURCE: American Heart Journal, December 2005.