Changes in type B natriuretic peptide (BNP) concentrations during cardiac valve replacement

OBJECTIVE: The aim of our study was to investigate the ability of BNP levels to reveal the immediate post-surgery cardiac function improvement. We measured the perioperative variations in BNP concentrations in patients scheduled for cardiac surgery with cardiopulmonary bypass (CPB), chronic mitral regurgitation, valvular aortic stenosis, or myocardial ischaemia. METHODS: Three groups were included: patients with coronary artery bypass graft (CABG, group I, n = 14), aortic (AVR, group II, n = 14) or mitral (MVR, group III, n = 7) valve replacement. BNP assay was performed at the induction of anesthesia, immediately after the CPB, at the arrival in the intensive care unit, 4 h, 8 h and 12 h after the arrival in ICU. RESULTS AND CONCLUSION: The occurring variation in BNP levels after the operation is an increase whatever the corrective surgery, underlying the relative lack of specificity of BNP with regard to the cardiac pathology. Besides iatrogenic cardioplegia one can supposes that cardiac surgery involves other major stimuli such as anesthesia, sternotomia, hemodynamics, post-operative that could influence in a non specific way BNP levels.