Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy

• Main Authors: L.M. Camargo, C.N. França, M.C. Izar, H.T. Bianco, L.S. Lins, S.P. Barbosa, L.F. Pinheiro, F.A.H. Fonseca
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 2014-05-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: Endothelial microparticles; Platelet microparticles; Platelet aggregation; Endothelial progenitor cells; Simvastatin/ezetimibe
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014000500432&lng=en&tlng=en

It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3<T1 and T4 for total cholesterol, LDL-C, and triglycerides; P<0.002 for all), as well as for endothelial function (T2>T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1<T3 and T4, P=0.034) and clopidogrel (adenosine, T3 and T4<T1 and T2, P<0.0001) therapy. Simvastatin/ezetimibe diphosphate did not change platelet aggregation, the amount of circulating endothelial and platelet microparticles, or endothelial progenitor cells. Cardiovascular protection following therapy with simvastatin/ezetimibe seems restricted to lipid changes and improvement of endothelial function not affecting the release of microparticles, mobilization of endothelial progenitor cells or decreased platelet aggregation.