Radial artery hypertrophy occurs in coronary atherosclerosis and is independent of blood pressure

Endothelial dysfunction, believed to underlie the structural changes of ath erosclerosis, is a systemic phenomenon. Despite this, the radial artery has been considered as devoid of atherosclerosis and is commonly used as a con duit in coronary artery bypass grafting (CABG). Recently, histological stud y has shown intimal hyperplasia and other structural changes consistent wit h early atherosclerosis in the radial artery. The objective of the present study was to determine if structural changes in the radial artery could be detected in vivo in patients with coronary atherosclerosis. Using high reso lution echo-tracking, measurements of radial artery internal diameter, wall thickness and wall cross-sectional area were made in 25 patients awaiting CABG and in 20 controls. Digital and brachial blood pressures were also rec orded. Mean arterial pressures did not differ between the patient and contr ol groups. All measures of wall thickness were greater in the patient than the control group. Neither current arterial pressures nor past history of h ypertension correlated with wall thickness. Using a model of analysis of co variance, coronary artery disease was the best single predictor of intima-m edia thickness, R-2 = 48%, n = 44, P < 0.0005. We concluded that increased radial artery wall thickness can be demonstrated in vivo in patients with c oronary atherosclerosis. This is a novel observation which seems to be inde pendent of blood pressure, and is consistent both with the hypothesis of sy stemic endothelial dysfunction leading to systemic structural changes and a lso to the recent histological evidence for atherosclerotic changes in this vessel.