Secretory phospholipase A2 activity and release kinetics of vascular tissue remodelling biomarkers after coronary artery bypass grafting with and without cardiopulmonary bypass

Background: Cardiopulmonary bypass (CPB) has long been recognised as a main cause of a postoperative complex systemic inflammatory response after coronary artery bypass grafting (CABG). Methods: We determined the kinetics of peripheral blood release of the novel inflammatory biomarkers secretory phospholipase A 2 (sPLA 2 ), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) during the first 6 days following surgery in 16 patients undergoing CABG with (on-pump, n =9) or without (off-pump, n =7) CPB. Kinetic curves for these markers were compared to those of the well-known inflammatory parameters C-reactive protein (CRP) and fibrinogen. Results: sPLA 2 activity exhibited a maximum value on day 2, then decreased until day 6 for both groups and in a similar manner as CRP levels. On the other hand, elevation of plasma levels of both MMP-9 and TIMP-1 occurred as early as on day 1 and remained at this level until day 6. No significant difference in kinetic characteristics (peak value, area under the curve, initial slope) between CABG with and without CPB was observed. Conclusions: These data show that the off- and on-pump groups did not show significantly different kinetics for the releases of all biomarkers studied, including sPLA 2 and biomarkers of the MMP-TIMP network. The off-pump procedure may therefore lead to global surgical trauma as important as CPB in terms of the systemic inflammatory process and matrix proteolysis pathway activation.