SYSTEMIC ENDOTHELIAL DYSFUNCTION IS RELATED TO THE EXTENT AND SEVERITY OF CORONARY-ARTERY DISEASE

Flow-mediated vasodilation (FMD) of systemic arteries, a non-invasive parameter of endothelial function, is correlated with cardiovascular r isk factors. The relationship between FMD and morphologically and clin ically evident coronary artery disease has not been described. This st udy was performed to test the hypothesis that an impairment of FMD in the brachial artery is related to the presence and/or extent and sever ity of coronary artery disease (CAD). We examined 74 patients with ang ina pectoris and 14 control subjects (age 17-36 years). Angiography re vealed coronary artery disease (greater than or equal to 30% diameter stenosis) in 44 patients (CAD, age 32-67 years) and smooth coronary ar teries in 30 patients (non-CAD, age 22-73 years). Vasodilation followi ng reactive hyperemia and after sublingual nitroglycerin (NTG) was ass essed in the brachial artery using B-mode high resolution ultrasound. CAD patients showed markedly impaired FMD compared to the non-CAD grou p (5.7 +/- 4.8 versus 12.6 +/- 6.7%, P < 0.0001) and to controls (5.7 +/- 4.8 versus 15.7 +/- 3.9%, P < 0.00001). NTG induced similar degree s of vasodilation in the CAD and non-CAD groups but less vasodilation in the CAD patients compared to controls (12.2 +/- 6.3 versus 20.4 +/- 6.9%, P < 0.01). On univariate analysis, impaired FMD in CAD patients and non-CAD patients was related to the extent of coronary disease (1 -, 2- or 3-vessel disease; r = -0.67, P < 0.0001), to the maximum perc ent diameter stenosis in one of the major coronary vessels (r = -0.52, P < 0.0001), brachial artery diameter (r = -0.46, P < 0.0001) and pla sma cholesterol level (r = -0.34, P < 0.001). On multiple stepwise reg ression analysis the extent of coronary disease (r = -0.51, P < 0.0001 ) and the baseline brachial artery diameter (r = -0.37, P < 0.0001) we re independently associated with FMD in CAD and non-CAD patients. The present findings suggest that the impairment of FMD in the brachial ar tery, a marker of systemic endothelial function, is closely related to the angiographic extent of CAD. (C) 1997 Elsevier Science Ireland Ltd .