Cardiopulmonary bypass contributes to less than half of interleukin-6 release post cardiac surgery

Introduction

IL-6 is an important marker for impairment of left ventricular function. Former studies have shown a significant release of IL-6 during coronary artery bypass grafting (CABG). The contribution of cardiopulmonary bypass (CPB) for IL-6-release and potential effects on decrease of the left ventricular function after CABG is still unknown. Therefore we examined three different types of revascularisation procedures which allowed us to estimate the CPB induced IL-6 release in CABG.

Methods

121 patients with coronary artery disease undergoing coronary revascularisation were examined in following groups: 1) Elective PTCA without CPB (n = 70), 2) CPB-supported PTCA (n = 8), 3) CPB-supported coronary artery bypass grafting (CPB-CABG; n = 41).

Results

1) The IL-6 plasma levels increased in all three groups to a significantly different degree with maximal IL-6 levels between 3 and 24 h after intervention. 2) The levels of the three collectives were significantly different at 3, 6, and 24 h (Table). 3) The correlation of IL-6 peak levels and duration of CPB was stronger in CPB-supported PTCA than in CPB-CABG.

Conclusion

The prolonged duration of the CPB may contribute to the development of a systemic inflammatory response syndrome (SIRS). Reduction of bypass duration or elimination of CPB, like it is performed in minimally invasive coronary bypass grafting, may be beneficial for patients and may further reduce the risk of SIRS.

Table IL-6 levels in three different groups of revascularisation procedure