Introduction: Concentrations of atrial (ANP) and brain (BNP) natriuretic peptides characterize chronic heart failure, which relates to outcome in patients with congenital heart defects. Time course and relation to perioperative parameters of these hormones have not been investigated during paediatric cardiac surgery .
Method: Following Ethic Committee approval and patient informed consent the data of 58 infants and children undergoing open heart surgery were prospectively investigated. ANP and BNP were measured before skin incision (T−1) at the end of surgery (T0) and 6, 12, 24 hours after surgery (T1, T2, T3, respectively). The following data was collected: demographics, diagnosis, intra-operative parameters (operation time, time of aorta cross-clamp and cardiopulmonary bypass (CPB), haemodynamics, inotropic support, fluid balance, transfusion). Blood samples were also drawn at T0 and T3 and creatine kinase and MB isoenzyme (CK, CKMB), lactate-dehydrogenase (LDH) and its heart isoenzyme (aHBDH), renal function, blood sugar, C reactive protein (CRP) were measured. Fluid balance, transfusion and inotropic support of the first 72 hours were also noted. Duration of mechanical ventilation (MV) and intensive care stay were also investigated. Statistical analysis consisted of Mann-Whitney U test and Spearman correlation and simple linear regression.
Results: Preoperative ANP levels were significantly higher in pulmonary hypertension (P < 0.001), in Down syndrome (P < 0.003), and in congestive heart failure (P < 0.02). BNP gave similar results (P: 0.01, 0.02 and 0.01, respectively). Increased duration of aorta cross-clamp time resulted in higher ANP concentrations at T2, T3 points (r: 0.61 and 0.65). ANP showed marked association with each LDH and aHBDH value (r: 0.36-0.57, P < 0.006), but neither with blood sugar, nor with CRP levels. BNP significantly correlated with the amount of inotropic support (T3 r: 0.56, P < 0.001), CKMB (T0 r: 0.44, P = 0.01) and renal function. ANP levels at each time point and BNP T0-T3 were significantly correlated with the duration of MV and intensive care stay. The best estimation for MV gave ANP (r: 0.69) and BNP (r: 0.71) at T2 time point.
Discussion: Our results indicate that ANP and BNP levels were proper indicators with respect to incidence of postoperative heart failure during paediatric cardiac surgery. Further investigations are needed to find the “normal” values and ranges of these hormones.
1 Bolger AP, Sharma R, Li W, et al. Neurohormonal activation and the chronic heart failure syndrome in adults with congenital heart disease. Circulation
2 Taggart DP, Hadjinikolas L, Wong K, et al. Vulnerability of paediatric myocardium to cardiac surgery. Heart