P-227: Effects of irbesartan on platelet aggregation and markers of inflammation in hypertensive patients with and without atherosclerotic cardiovascular disease

Clinically evident atherosclerotic cardiovascular disease (ASCVD) is a pro-inflammatory state associated with increased platelet aggregability (PAGG) and activation of the renin angiotensin system. We hypothesize that: a) in hypertensive patients a selective angiotensin II AT1 receptor antagonist Irbesartan (IRB) in addition to its hypotensive effect may also contribute to reduction of PAGG and of plasma markers of inflammation; b) these effects of IRB are different in patients with and without ASCVD. This randomized, double-blind, placebo-controlled crossover study was performed in 18 non-smokers with Stage I hypertension (10 pts w/o ASCVD [Group A; 60% males; 50% whites]; 8 pts w/ASCVD [Group B; 63% males; 50% white]). Nine pts had hyperlipidemia (8 treated with statins). Patients received IRB or placebo for 6 weeks each (the IRB dose was uptitrated from 150 mg to 300 mg after 3 wks), with a 4-wk wash-out. No antiplatelet, or antidepressant agents, or NSAID were permitted. PAGG was tested with thrombin-receptor agonist (TRA) and adenosin-diphosphate (ADP). Plasma concentration of CRP, IL-6, P-and E-selectins were obtained at baseline and at the end of each treatment period. IRB treatment decreased SBP (mean ± SD mm Hg; from 146.4 ± 12.4 to 140.7 ± 10.3; p