Peri-operative myocardial tissue injury and the release of inflammatory mediators in coronary artery bypass graft patients

Abstract

Objective: This study was conducted to evaluate to what extent the ischemia-reperfusion injury resulting from the cardiopulmonary bypass (CPB) and aortic cross-clamping procedures during coronary artery bypass grafting (CABG) contributes to the systemic inflammatory response generally found in these patients.

Methods: Serum levels of enzymes (CK and CK-MB) and non-enzymatic proteins (FABP and myoglobin) as markers of myocardial tissue injury, bactericidal permeability increasing protein (BPI) as an indicator of neutrophil activation, interleukin-6 (IL-6) as inducer of the acute phase response and lipopolysaccharide binding protein (LBP) as parameter of the acute phase response were measured in 15 low-risk CABG patients with cardiopulmonary bypass (CPB), and 17 low-risk CABG patients without CPB.

Results: Already 0.5 h after reperfusion significantly increased plasma levels of all markers of myocardial tissue injury were noted in patients having surgery with CPB, but not in non-CPB patients. No significant differences were found between both groups for BPI and IL-6 levels in the early reperfusion period. BPI and IL-6 levels were higher in the non-CPB group on the first post-operative day (P < 0.05). However, no correlations were found for any marker of peri-operative tissue damage with either early neutrophil activation, or acute phase reactants.

Conclusions: Perioperative myocardial injury resulting from CPB and aortic cross-clamping in low-risk CABG patients does not contribute to the release of inflammatory mediators in these patients.