Cytokine responses in patients undergoing coronary artery bypass surgery after ischemic preconditioning

Objective-The release of proinflammatory cytokines has been shown to be ass ociated with the development of complications after coronary artery bypass grafting with cardiopulmonary bypass. The purpose of the present study was to establish whether ischemic preconditioning (IP) could limit inflammatory cytokines release in patients undergoing elective coronary artery bypass s urgery. Methods-Twenty-two patients with multiple-vessel coronary artery disease an d stable angina admitted for first-time elective coronary artery bypass sur gery were randomized into control or ischemic preconditioning groups. Patie nts in the IP group were exposed to two cycles of two-minute myocardial isc hemia, followed by three minutes of reperfusion, at the beginning of the re vascularization operation, before the cross-clamping and ischemic period us ed for coronary artery bypass graft anastomosis. Peripheral plasma levels o f TNF-alpha, IL-6, IL-8 and IL-IO were measured perioperatively. Results-Significant elevation of IL-6, IL-8 and IL-IO were observed in both groups after reperfusion. Ischemic preconditioning has no effect on cytoki ne release in the early stage after reperfusion. Arterial blood IL-6 levels in the preconditioning group were significantly lower than in controls at 20 h after declamping (52.93 +/- 9.79 vs 96.04 +/- 17.56 pg/ml, p < 0.05), Conclusions-The results indicate that ischemic preconditioning results in n o effect on systemic inflammatory cytokine release in the early stage but a delayed reduction in IL-6 levels at 20 h after reperfusion.