Analysis of inflammatory response and utility of N-terminal pro brain-type natriuretic peptide in cardiac surgery with extracorporeal circulation

OBJECTIVES: Cardiac surgery with cardiopulmonary bypass (CPB) elicits an inflammatory response. During and after cardiac surgery, we examined the pattern of cytokine release of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-alpha, to investigate inflammatory response. We analyzed N-terminal pro brain-type natriuretic peptide (NT-proBNP) as a marker of ventricular function. METHODS: Consecutive patients (n = 58) undergoing elective cardiac surgery with extra-corporeal circulation were recruited into the study. Blood samples for analysis of the biochemical markers were taken at seven time points for cytokines and TNF, and three for Nt-proBNP. RESULTS: All markers increased significantly after CPB. IL-6 and IL-8 levels were higher in men. IL-8 was related to a need for inotropic support. IL-6 was related to the time of CPB (P = 0.004), aortic clamping (P = 0.013), length of stay in intensive care unit (ICU) (P = 0.004) and mechanical ventilation for more than 12 h (P = 0.006). The levels of NT-proBNP were higher in cases of ventricular dysfunction (P = 0.003) and functional class III/IV (P = 0.001). The postoperative values were related to age (P < 0.05), creatinine values (P < 0.001), mechanical ventilation time (P < 0.001) and stay in the ICU (P = 0.001). CONCLUSION: Our data indicate a relationship between cytokine levels and sex, time of CPB and aortic clamping, The increase of cytokines correlates with a need for inotropic support, mechanical ventilation and length of stay in ICU. We confirmed the predictive role, and its utility in the risk stratification of the NT-proBNP, and its importance in early diagnosis of postoperative ventricular dysfunction.