New research indicates that individuals who have a brother or sister who developed heart disease at a young age may have an increased risk of also having heart disease.

In fact, having a sibling with early heart disease appears to be a stronger predictor than having a parent with heart disease.

Dr. Roger S. Blumenthal, from Johns Hopkins Hospital in Baltimore, and colleagues assessed 8,549 subjects with no symptoms of heart disease for coronary artery blockages. The subjects were also asked about a family history of premature coronary heart disease.

The researchers’ findings appear in Circulation: Journal of the American Heart Association.

Subjects with a family history of premature coronary heart disease, particularly a sibling history, were more likely to have coronary artery plaques than those lacking such a history.

Among men, the prevalence of coronary artery plaques was 55 percent, 64 percent, and 78 percent for subjects with no family history of coronary heart disease, an affected parent, and an affected sibling, respectively. The corresponding rates in women were 27 percent, 36 percent, and 56 percent.

Having a parent with early heart disease increased the risk by about 30 percent, while having a sibling with early heart disease more than doubled the risk.

The new findings “demonstrate for the first time that sibling history of premature coronary heart disease is more strongly associated with coronary atherosclerosis than a parental family history of premature coronary heart disease,” the investigators state.

Based on these findings, the investigators suggest that middle-age patients with family history of premature coronary heart disease be evaluated to help determine what risk factors may be modified to lower their risk of a heart attack, they add.

SOURCE: Circulation 2004.