The relationship between endothelial function in the brachial artery and intima plus media thickening of the coronary arteries in patients with chest pain syndrome.

Endothelial dysfunction precedes the development of clinical atherosclerosis. A decrease in endothelium-derived nitric oxide activity shows impaired vasodilator function and causes arterial intimal hyperplasia or thickening. Others and we have reported the close relation of endothelial function in brachial artery and coronary artery. To compare the flow-mediated endothelium-dependent vasodilation (FMD) in brachial artery and the intima+media area in coronary artery, we measured brachial artery vasodilator response following transient occlusion with high resolution ultrasound transducer and intima+media area in coronary arteries with intravascular ultrasound in 25 patients with normal coronary angiograms (age 61.6+/-8.7 years old, men 14 and women 11). FMD was measured at least 7 days after the cessation of all vasodilators. The mean FMD of 25 patients was 3.83+/-2.38%, the mean intima+media area in coronary arteries of 25 patients was 39.9+/-15.5% of total vessel wall. FMD has a close negative relation with the largest percent intima+media area (r=-0.77, p<0.01). Especially, the patients whose FMD was less than 3.83% had larger percent intima+media area than those whose FMD was 3.83% or more (48.7+/-10.7% versus 30.3+/-14.2%, p<0.01). There is an intima+media thickening even in the patients who had normal coronary angiograms, and that the percent intima+media area correlated with FMD. The measurement of FMD is useful for screening the coronary artery intima+media thickening noninvasively. The pathogenesis of acute coronary syndrome has been reported to be the plaque rupture even in the patients with normal coronary angiograms. Thus, we must pay much attention in the patients with impaired FMD even in the normal coronary angiograms.