Rapid effect of pravastatin on endothelial function and lipid peroxidation in unstable angina

Background Oxidative stress contributes to endothelial dysfunction, an important step to the pathogenesis of atherosclerosis and coronary events. Latest studies revealed the existence of pleiotropic and especially antioxidant properties of statins. We sought to examine the effects of pravastatin on lipid peroxidation and endothelial function, independently from lipid-lowering, in patients with unstable angina (UA). Methods Thirty-seven patients (males), 64.46±9.09 years, suffering from UA enrolled in the study. Patients were not on statin medication before admission and they received after randomization either 40 mg pravastatin daily (group A, n=20), or placebo (group B, n=17). Malondialdehyde (MDA) concentration, an index of lipid peroxidation and plaque instability, flow-mediated dilatation (FMD) of the brachial artery and blood lipids were measured on the second day of hospitalization and 10 days later. Results MDA decreased significantly in both groups (A, p=0.008; B, p=0.003). FMD increased significantly in group A (p=0.007), whereas in group B it did not change. Serum lipids remained unaltered in all three groups. Conclusions Pravastatin administration improved FMD within 10 days and this favorable effect occurred before any significant reduction in blood lipids, revealing its pleiotropic effects during the early phase of an acute coronary syndrome. Circulating lipid peroxidation products in patients with UA decreased significantly during the same period independently of endothelial function and pravastatin therapy.