Perioperative Changes In Serum Brain Natriuretic Peptide Concentrations In Patients Undergoing Cardiac Surgery

Objective B-type natriuretic peptide(BNP) is a neurohormone with diuretic, natriuretic and vasorelaxant properties, which synthesized in the cardiac ventricles. Release appears to be in direct proportion to ventricular volume expansion and ressure overload, it increases in patients along with increases in the severity of congestive heart failure. BNP levels accurately reflect the decompensated state of circulatory congestion. It is a sensitivity and specific in diagnosis of cardiac function. This study was to investigate the perioperative changes of serum brain natriuretic peptide concentrations in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) and non- cardiopulmonary bypass(N-CPB).Methods We studied 33 consecutive subjects, 13 patients with CAD submitted to off-pump coronary bypass and 20 patients with RHD submitted to cardiac valve replacement with CPB. The preoperative NYHA cardiac function and the left ventricular ejection fraction(LVEF), left ventricular end-dyastolic diameter (LVEDD) were measured by echocardiogram. BNP were measured at preoperation, postoperation, postoperatively 24 hours, 3 days and 7days after, respectively.Results (1)The preoperative BNP was high, after surgery it was similar to preoperative BNP level, it elevated markedly and acutely to a peak value 24 hours after operation (p<0.001) and then decreased after that; after 7 days later, it was still higher than the concentration before operation (p<0.05). (2) Changes in BNP concentrations following open cardiac surgery with and off-pump surgery was similar. (3)There was a positive correlation between NYHA and BNP (r=0.8 p<0.01), but no correlation between LVEF and LVEDD.Conclusion The preoperative serum BNP concentration is sensitivity and specific in diagnosis of preoperative cardiac function, it correlated sig- nifycantly with NYHA cardiac function; the serum concentrations of BNP become markedly and acutely elevated after cardiac surgery, the level of blood BNP reached a peak 24 hours after operation and then decreased after that, 7days later it was still high, the changes of BNP in CPB and N-CPB was similar.