Abstract: Objective To explore the variance of plasma brain natriuretic peptide (BNP) concentrations in the aged patients after noncardiac surgery and its significance. Methods 101 patients undergoing elective noncardiac surgery were divided into two groups based on the BNP concentrations before surgery: group A: BNP≤100 ng/L，n=61; group B: BNP>100 ng/L，n=40. The BNP concentrations before and after noncardiac surgery and the incidence of cardiac events in both groups were compared. Results There was no significant difference （P>0.05） of BNP concentrations before and after noncardiac surgery in group A, which were (58.2±28.7) ng/L and (53.7±25.9) ng/L respectively, but was significant difference （P<0.05） in group B, which were (147.3±72.1) ng/L and (341.5±92.4) ng/L respectively. There was significant difference （P<0.05） between group A, in which no patient happened cardiac event, and group B, in which 14 patients happened. Conclusion The plasma BNP concentration would be increased significantly in the aged patients with a BNP concentration>100 ng/L before surgery, which may cause more cardiac events.

Key words: aged, brain natriuretic peptide (BNP), noncardiac surgery, cardiac events