Jan 12 2009
Even younger adults who have few short-term risk factors for heart disease may have a higher risk of developing heart disease over their lifetimes, according to new findings by a UT Southwestern Medical Center researcher.
The findings, based on clinical studies and appearing in the Jan. 19 issue of the journal Circulation: Journal of the American Heart Association , suggest that traditional methods of identifying heart disease risk might not adequately identify patients who actually have a higher lifetime risk.
"We found that about half of individuals who are 50 years of age or younger and at low short-term risk for heart disease may not remain at low risk throughout their lives," said Dr. Jarett Berry, assistant professor of internal medicine at UT Southwestern and lead author of the study.
Using current 10-year risk assessment data, more than 90 percent of patients 50 years of age and younger are considered at low risk for heart disease. But when researchers added a lifetime risk model to the 10-year risk model, they found that about half of those with a low 10-year risk but high lifetime risk had a greater progression of heart disease, as measured by buildup of coronary artery calcium and thickening of the carotid artery.
The short-term (10-year) risk factors in the study were represented by the Framingham Risk Score, a tool typically used by physicians to assess risk for heart disease in patients. Risk factors listed on the assessment include cholesterol levels, blood pressure, smoking, age and gender.
"There is a discrepancy between short-term and long-term risk," Dr. Berry said. "People deemed low-risk, using the 10-year assessment, may not remain low-risk throughout their lives."
About 4,000 adults younger than 50 were divided according to their short-term risk for heart disease. For those with low short-term risk and without diabetes, the researchers also estimated the lifetime risk using factors such as blood cholesterol levels, smoking and blood pressure.
"When we compared the people with low short-term but high lifetime predicted risk with those individuals who had low short-term and low lifetime predicted risk, we found that the former group had a greater prevalence and progression of atherosclerosis," Dr. Berry said. "Thus, long-term risk estimates in younger patients may provide new information regarding risk prediction that is not usually available using only a 10-year risk model."
Dr. Berry added that because such an estimate has a profound association with subclinical atherosclerosis at this young age, it further supports the notion that long-term risk estimation could be a useful addition to current clinical practice. In particular, a long-term risk estimate could be used in combination with a short-term risk estimate to counsel patients more effectively, especially younger adults with risk factors for heart disease.