News - Hypertension Week of Sept 21, 2003/ Vol. 2 No. 38

Study: High Blood Pressure Plays Only a Small Role in Aortic Aneurysms

High blood pressure plays only a small role in causing the dangerous ballooning of blood vessels that can lead to an aneurysm, according to a study reported in the Journal of the American College of Cardiology.

Study author and Mayo Clinic cardiologist Dr. Bijoy Khandheria said it was always believed that atherosclerotic plaques and the risk factors that cause them, including hypertension, were important potential causes of the expansion of the aorta.

"Intuitively, it makes sense that high blood pressure would stretch the vessel walls and make them more likely to become enlarged," said Khandheria. "This study shows that while these risk factors are highly important in a host of diseases and conditions, they are bit players when it comes to causing the dilatation of the aorta that can lead to aneurysm."

Khandheria and his colleagues studied the expansion of the aorta in a sample of 581 study participants from Minnesota and found that age, gender and body size together accounted for one-third or more of the cases of aortic dilatation, while atherosclerosis and related risk factors only explained 3 percent.

"There has been a tendency recently to refer to aneurysms as athersclerotic aneurysms," said Khandheria. "But the fact that plaques…are very common, while aneurysms are rare, supports the conclusion that atherosclerosis and its risk factors are not likely to blame for aneurysms in the major blood vessels of the chest.

Khandheria said other factors and processes, including genetic diseases similar to Marfan syndrome, seem to be more important.

"In addition to providing reference values to physicians on the normal range of aorta measurements in a community, this study should spur further investigation into those other causes," Khandheria said.

Other sources: Mayo Clinic