The myocardial protective effect of adenosine as an adjunct to intermittent blood cardioplegia during open heart surgery.
OBJECTIVE The release of proinflammatory cytokines has been shown to be associated 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 surgery. METHODS Twenty-two patients with multiple-vessel coronary artery disease and stable angina admitted for first-time elective coronary artery bypass surgery were randomized into control or ischemic preconditioning groups. Patients in the IP group were exposed to two cycles of two-minute myocardial ischemia, followed by three minutes of reperfusion, at the beginning of the revascularization operation, before the cross-clamping and ischemic period used for coronary artery bypass graft anastomosis. Peripheral plasma levels of TNF-alpha, IL-6, IL-8 and IL-10 were measured perioperatively. RESULTS Significant elevation of IL-6, IL-8 and IL-10 were observed in both groups after reperfusion. Ischemic preconditioning has no effect on cytokine 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 no effect on systemic inflammatory cytokine release in the early stage but a delayed reduction in IL-6 levels at 20 h after reperfusion.