Introduction: Endothelial dysfunction plays a crucial role in the process of atherosclerotic diseases and has been accepted as an early stage of atherosclerosis. Carotid intima-media-thickness (CIMT) and flow-mediated-dilatation (FMD) of the brachial artery have been recommended as noninvasive methods to assess endothelial structure and function. Angiographic properties of patients with acute coronary syndrome (ACS) are closely associated with cardiovascular events. In this study, we investigated the relation of atherosclerotic properties of coronary, brachial and carotid arteries with CIMT, FMD and coronary angiography in patients with ACS.

Methods: We enrolled 133 patients who were diagnosed with ACS into this study. Exclusion criteria were known coronary artery disease, diabetes mellitus and hypertension. Coronary angiography, CIMT and FMD were measured in all patients. The numbers of major stenotic coronary vessels with > or = 50% or > or = 70% were defined as diseased vessel. Gensini score was used to evaluate the severity of atherosclerosis. Morphologic properties of stenotic lesion were defined. Cutoff levels were 7% for FMD and 0.9 mm for CIMT.

Results: Mean age was 59.7 + or - 11.8 years. FMD, CIMT and Gensini score were 8.3 + or - 5.9%, 0.80 + or - 0.19 mm and 7.8 + or - 3.5, respectively. Only 44% of patients with ACS had impaired FMD. Gensini score, number of diseased vessels and number of critical lesions were higher in patients with impaired FMD. (Gensini: 8.7 + or - 3.6 vs. 7.0 + or - 3.1, p = 0.009, diseased vessels: 2.7 + or - 0.4 vs. 2.3 + or - 0.7, p < 0.0001, critical lesions: 3.0 + or - 2.1 vs. 2.2 + or - 1.4, p = 0.02). Increased CIMT was found in only 33% of patients. Gensini score and number of diseased vessels were significantly higher in patients with increased CIMT. Significant but weak correlations were found between CIMT, FMD and angiographic severity of coronary atherosclerosis. Angiographic properties and lesion morphology were similar between CIMT and FMD groups.

Conclusion: There appears to be a relationship between CIMT, FMD and severity of coronary atherosclerosis in patients with ACS. However, in patients with ACS, morphologic properties of stenotic lesions are not associated with CIMT and FMD in brachial artery.