Genes may partially determine the locations of plaques within the coronary artery system, with data suggesting that some of the most dangerous plaque locations have a high heritability, according to an article published online February 14th by Circulation.

“Different locations of disease show different degrees of inheritance. The most hazardous ones have a high heritability,” said Ulrich Broeckel, MD, a study coauthor. He added, “As far as we can determine, we are the first to do a large study of the genetic contribution to the location and pattern of coronary lesions.”

The new findings, if confirmed, could affect heart disease screening strategies for close relatives of patients with coronary heart disease.

The American-German team conducted the current study as part of a10-year collaboration. The researchers studied angiograms of 882 siblings with coronary artery disease from 401 families. One person from each family had had a myocardial infarction before age 60 years and at least one sibling had had a myocardial infarction or coronary revascularization procedure.

The team compared angiograms of the 401 patients with that of a sibling who had had a myocardial infarction or revascularization procedure. They found that a large number of sibling groups had shared disease patterns, indicating a genetic influence.

After considering several factors that affect the risk of coronary disease, such as age, gender, hypertension, and diabetes, an analysis showed a statistically significant association between inheritance and coronary heart disease at the point where the coronary arteries branch from the aortic artery, as well as in the upper parts of the left and right coronary arteries, the degree of artery ectasia, and the amount of calcified artery deposits.

The researchers found a lesser degree of statistically significant influence, or none at all, between heredity and coronary disease in the lower parts of the heart’s left and right arteries, diffuse disease, the pattern of blood supply, and whether a person had disease in one, two or three arteries.

The researchers did not design the study to reveal the actual genes that might influence disease development at different artery sites. “That is our next step,” Broeckel said. The study findings may help improve screening for relatives of people with coronary heart disease, he said. For example, the genetic link to disease in the left main artery may offer a more precise way to predict a relative’s risk of having or developing the same problem.

The researchers noted several limitations of the study that could affect its results. All participants were white and of northern European origin, which means the genetic findings might not apply to other ethnic groups. Moreover, the study did not consider to what degree the siblings shared the same living environment, which could mean an overestimation of the genetic role in disease at specific sites.