Plasma levels of atrial and brain natriuretic peptides as indicators of recovery of left ventricular systolic function after coronary artery bypass

OBJECTIVE: The purpose of this study was to investigate the effectiveness of atrial and brain natriuretic peptides (ANP and BNP, respectively) as indicators of recovery of left ventricular (LV) function after coronary surgery. METHODS: We measured the concentrations of these peptides in 31 patients with poor LV function (ejection fraction, EF<35%) undergoing coronary artery bypass, and evaluated their correlation with the echocardiographic indexes of LV function. RESULTS: Pre-operatively, the plasma levels of both ANP and BNP were markedly higher in coronary patients than in normal control subjects, and strongly correlated with both EF (BNP: r=-0.8, P<0.001; ANP: r=-0.6, P<0.001) and wall motion score index (WMSI). At post-operative follow up, plasma levels of both natriuretic peptides were markedly reduced compared with pre-operative values in 21 patients. In addition, the post-operative-pre-operative differences of BNP (Delta(BNP)) and ANP (Delta(ANP)) plasma levels strongly correlated with the differences of both EF (r=-0.7, P<0.0001 vs. Delta(BNP); r=-0.6, P=0.0003 vs. Delta(ANP)) and WMSI (r=0.6, P=0.002 vs. Delta(BNP); r=0.6, P=0.04 vs. Delta(ANP)). Finally, by logistic regression analysis, BNP appeared a significant predictor of LVEF recovery after surgery. CONCLUSION: Plasma levels of ANP and BNP might be used in routine clinical practice as a support to echocardiography in detecting recovery of the LV function after coronary surgery.