Irbesartan, an angiotensin type 1 receptor inhibitor, regulates markers of inflammation in patients with premature atherosclerosis

Objectives This study assessed the role of angiotensin II type 1 (AT(1)) receptor antagonists on inflammatory mechanisms involved in atherogenesis. Specific inflammatory markers included solubilized tumor necrosis factor-alpha receptor II (sTNF-alpha RII), vascular cell adhesion molecule-1 (VCAM-1) and superoxide. In addition, the AT(1) receptor blocker irbesartan was evaluated for its ability to suppress these markers in individuals with atherosclerosis. Background Mechanisms involved in the complex process of atherogenesis include alterations in the inflammatory responses. The use of compounds that suppress these responses may reduce the degree of damage seen in atherosclerosis. Methods With a cross-sectional study design, 33 normotensive patients with stable coronary artery disease (CAD) were treated with irbesartan for a 24-week period. These patients were compared against a control population with no known coronary atherosclerosis. Marker levels were measured by enzyme-linked immunosorbent assay technique and lucigenin chemiluminescence assay and statistically evaluated by two-way repeated measures analysis of variance. Results All patients with coronary artery disease had increased levels of inflammatory molecules over those of control patients. Treatment with irbesartan in these patients significantly reduced levels of inflammatory molecules measured. Soluble VCAM-1 levels were reduced by 36%; soluble TNF-alpha levels were reduced by 54% and superoxide level decreased by 52%. Maximal suppression of inflammatory markers by irbesartan therapy in patients with CAD was seen at 12 weeks. Conclusions The effect of irbesartan on each inflammatory marker is significant. Our results show that use of irbesartan may retard the inflammatory process seen in premature forms of atherosclerosis. (C) 2001 by the American College of Cardiology.