Plasma Brain Natriuretic Peptide after Isolated On-Pump Coronary Artery Bypass Grafting: Prediction of Postoperative Adverse Outcomes

Abstract

The heart is an endocrine organ that synthesizes 2 different natriuretic peptides: atrial natriuretic peptide and brain natriuretic peptide (BNP). We assessed the relationship between preoperative BNP levels and postoperative complications and outcomes in patients who undergo isolated coronary artery bypass grafting (CABG). The study consisted of 85 patients undergoing first-time elective CABG. Preoperative BNP levels were significantly correlated with the preoperative ejection fraction (P = .004), the number of vessels grafted (P = .016), cross-clamp time (P = .041), and perfusion time (P = .032). Preoperative BNP levels were higher in patients who developed postoperative new-onset atrial fibrillation (AF) (median BNP, 197 pg/mL versus 65 pg/mL; P = .006), in patients requiring inotropic support (189 pg/mL versus 65 pg/mL; P = .004), and in patients who required an intra-aortic balloon pump (IABP) (325 pg/mL versus 68 pg/mL; P= .021). Analysis of receiver operating characteristic curves demonstrated the preoperative BNP level to be a predictor of new-onset AF, a need for inotropic support, and a requirement for an IABP (areas under the curve, 0.70, 0.70, and 0.79, respectively). BNP cutoff values of 100 pg/mL for AF, 185 pg/mL for inotropic support, and 235 pg/mL for requiring an IABP predicted these postoperative adverse outcomes with 65%, 73%, and 84% accuracy, respectively. This study suggests that a higher baseline plasma BNP concentration is associated with postoperative new-onset AF, a need for inotropic support, and an IABP requirement in patients who undergo first-time isolated CABG.