RESUMO
INTRODUCTION AND AIMS: In patients with coronary risk factors the presence of endothelial dysfunction in epicardial arteries has been documented. The purpose of this study was to determine whether endothelial dysfunction, documented hypercholesterolemic patients and angiographically normal coronary arteries, improves by reduction and normalization of lipid levels. PATIENTS AND METHOD: In 10 patients with hypercholesterolemia and normal coronary angiography, the endothelium-dependent coronary vasomotion was studied by intracoronary infusion of acetylcholine into the left anterior descending coronary artery. Vasomotion changes in response to acetylcholine were analyzed by quantitative angiography. Five patients without coronary risk factors and normal coronary arteries formed the control group. Patients with hypercholesterolemia were treated with lipid-lowering therapy (diet and lovastatin) and endothelial function was reevaluated after 24 +/- 4 months. RESULTS: In the initial study, hypercholesterolemic patients compared with the control group showed a vasoconstrictor response to serial doses of acetylcholine(10(-6) M, 10(-5) M, 10(-4)M) indicative of endothelial dysfunction (study group: -0.3 +/- 10%, -6 +/- 4%, -18 +/- 10% vs control group: -0.6 +/- 6%, -2 +/- 6%, 3+/-6%; p < 0.01 to 10(-4) M acetylcholine dose. During follow-up hypercholesterolemic patients who a significant reduction in total cholesterol levels and LDL. Compared to first study, at follow-up, there was an improvement in the response to acetylcholine (-0.4 +/- 4%, -3 +/- 6%, -3 +/- 10%; p<0.001 vs basal values at 10(-4) M acetylcholine concentration). Reduction in total cholesterol during follow-up was related to the improvement in the vasoconstrictor response to acetylcholine (r=0.53; p< 0.05). CONCLUSION: In patients with hypercholesterolemia and angiographycally normal coronary arteries with documented endothelial dysfunction, the reduction and normalization of lipid levels during follow-up may improve endothelium-dependent coronary vasomotion.
