 Agents that attenuate the renin angiotensin system RAS, i.e. angiotensin converting enzyme inhibitors ACE-Is and angiotensin receptor blockers ARB, have shown to have therapeutic benefit in a variety of cardiovascular disorders. ACE-Is are considered standard of care for secondary prevention of CAD by the AHAACC. Based on the HOPE study, the beneficial effects of ACE-Is in patients at high risk for cardiovascular outcomes may be beyond mere blood pressure control. In addition to their effects on blood pressure, aldosterone, and sodium and water absorption, blockade of the RAS with ACE-Is or ARBs alter key biomarkers of vascular inflammation, vascular endothelial function, and fibrinolytic balance. These surrogate biomarkers are thought to play a role in the progression of atherosclerosis. Biomarkers of vascular inflammation include vascular and intracellular cell adhesion molecule VCAM and ICAM respectively and c-reactive protein CRP. Markers of endothelial function include endothelin-1 ET-1 and the vasodilator nitric oxide NO. Plasminogen activator inhibitor-1 PAI-1 is a prothrombotic marker associated with plaque proliferation and atherosclerosis progression. 