Preoperative B-type natriuretic peptide, and not the inflammation status, predicts an adverse outcome for patients undergoing heart surgery

Abstract

Objectives: B-type natriuretic peptide (BNP) and inflammatory markers are implicated in the pathophysiology of both ischemic cardiomyopathy and complications after cardiac surgery with cardiopulmonary bypass (CPB). The purpose of this study was to assess preoperative and postoperative levels of BNP, interleukin-6 (IL-6), interleukin-8 (IL-8), P-selectin, intercellular adhesion molecule (ICAM), C-reactive protein (CRP) in patients undergoing cardiac surgery with CPB and investigate their variation and ability to correlate with immediate outcome. Methods: Plasma levels of these markers were measured preoperatively, 6 and 24 h after CBP in 62 patients. Main endpoints were requirements for intra-aortic balloon pump, intensive care unit (ICU) stay longer than five days, ventilator dependence >24 h, requirement for dobutamine, hospital stay >10 days, clinical complications (infection, myocardial infarction, renal failure, stroke and ventricular arrhythmias) and in-hospital mortality. Results: Preoperative BNP levels correlate with longer ICU stay (P=0.003), longer ventilator use (P=0.018) and duration of dobutamine use (P<0.001). The receiver-operating characteristic curve demonstrated BNP levels >190 pg/ml as predictor of ICU >5 days and BNP levels >20.5 pg/ml correlated with dobutamine use, with areas under the curve of 0.712 and 0.842, respectively. Preoperative levels of ICAM-1 were associated with in-hospital mortality (P=0.042). In the postoperative period, was found association between CRP, IL-6 and P-selectin with ventilation duration (P=0.013, P=0.006, P<0.001, respectively) and P-selectin with ICU stay (P=0.009). Conclusions: BNP correlates with clinical endpoints more than inflammatory markers and can be used as a predictor of early outcome after heart surgery.