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

Abstract

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. 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. 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). 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.