Vasomotor responses of coronary stenoses to acetylcholine and their relation to serum lipid levels in stable angina pectoris

The effects of acetylcholine administration on coronary stenoses in relatio n to serum lipids level were evaluated in 18 patients (15 men, 3 women) wit h coronary artery disease and stable angina. Intracoronary acetylcholine wa s infused in concentrations 10(-7), 10(-6)' 10(-5) M, followed by intracoro nary bolus administration of isosorbide dinitrate, Computerized angiography was used to assess the changes in the diameter of stenoses and of proximal and distal segments. During acetylcholine infusion, at concentrations betw een 10(-7) to 10(-5) M, there was a significant (p < 0.01) dose-dependent c onstriction of proximal and distal segments and of stenoses reversed by iso sorbide dinitrate. There was no correlation between the serum total cholest erol level and the responses of proximal and distal segments to acetylcholi ne or nitrate. A correlation (p < 0.05) was found between the serum total c holesterol level and the response of stenoses to acetylcholine, but there w as no correlation with the response to isosorbide dinitrate. In conclusion, in patients with stable angina current serum total cholesterol level corre lates with the vasomotor response of coronary stenoses to intracoronary ace tylcholine, These findings are consistent with a direct effect of cholester ol, increasing basal coronary vasomotor tone and increasing the stimulated vasoconstrictor response of stenoses. (C) 1999 by Excerpta Medico, Inc.