Relationship between plasma B-type natriuretic peptide and ventricular function in adult cardiac surgery patients

Plasma concentrations of B-type natriuretic peptide (BNP) were analysed during the peri- and post-operative periods in cardiac surgery patients, and the relationship between plasma BNP concentrations and various clinical parameters was explored. Thirty patients (17 women, 13 men) of age 54.5 +/- 17.1 years undergoing cardiac surgery between June 2004 and March 2005 were enrolled. Plasma BNP concentrations were measured pre-operatively, immediately post-operatively, and on the first, second, fourth and seventh post-operative days. On the first post-operative day, the BNP level was significantly increased but levels returned to baseline values by the seventh post-operative day. The pre-operative BNP level correlated with left ventricular ejection fraction and age, and the level 24 h after surgery correlated with left ventricular end-diastolic dimension and pre-operative BNP levels. These results showed that the plasma BNP concentration becomes markedly and acutely elevated after cardiac surgery, reflecting temporary ventricular dysfunction.