Brain natriuretic peptide (BNP) in patients undergoing coronary artery bypass grafting

This study was designed to examine plasma concentrations of BNP and its relation to hemodynamic parameters in patients (pts.) with coronary artery disease (CAD) undergoing coronary artery bypass grafting (CABG).

21 pts. with CAD undergoing CABG were examined. The pts. were divided into two groups. Group I: normal left ventricular function (LVF); Group II: reduced LVF. Pre-, intra- and postoperative BNP and hemodynamic parameters were measured. The perioperative administration of inotropic drugs was documented.

In both groups postoperative BNP increased to a peak 24 h postoperatively; although BNP concentrations were high 24 h postoperatively hemodynamic parameters were improved in both groups. In Group I the BNP peak did not correlate with any hemodynamic parameter nor with the use of inotropic drugs. In Group II the BNP peak was inversely correlated with CO and CI and positively correlated with the PCWP. There was no correlation with inotropic support.

Postoperative peak of BNP after 24 h does not reflect a state of acute perioperative heart failure or myocardial damage. These results suggest that the gene expression, metabolism and biological activity of BNP may be altered after extracorporeal circulation. Further studies are warranted to reveal the actual triggers for BNP increase early after CABG.