The anti-inflammatory effect of bradykinin preconditioning in coronary artery bypass grafting (bradykinin and preconditioning)

Objective. The present study was designed to investigate the cardioprotective effect of exogenous administration of bradykinin (BK) in cardiac surgery. Methods. Forty-one patients who were scheduled for isolated coronary artery bypass grafting (CABG) were randomized into Control group and BK group. BK patients received 25 g bradykinin infusion for 7 minutes before the cardiopulmonary bypass (CPB). Release of cardiac specific troponin I (TnI) and creatine kinase cardiac isoenzyme (CK-MB) was recorded. Perioperative circulating cytokine interleukin (IL)-6, 8 and 10 were measured. Results. There was no significant difference in TnI between groups. However, BK patients released significantly less CK-MB than the controls (p =0.043). Systemic plasma levels of IL-6, IL-8 and IL-10 increased significantly after reperfusion in both groups as compared with baseline (p 0.05). The ratio of IL-8 to IL-10 was significantly lower in BK groups than in controls (p =0.03). Conclusions. We conclude that exogenous administration of BK prior to CPB in CABG patients attenuates ischemic myocardial injury. It also shifts the circulating inflammatory cytokine balance towards the anti-inflammatory direction.