Prognostic value of plasma N-terminal pro-brain natriuretic peptide in children with congenital heart defects and open-heart surgery

Objective

To assess whether preoperative and postoperative plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) predict postoperative outcome of open-heart surgery in children.

Study design

A prospective observational study was conducted with 40 children with congenital heart defects who were undergoing elective open-heart surgery. Plasma levels of NT-proBNP, troponin T, lactate, C-reactive protein, and total neutrophil cell counts were measured before, during, and 1 and 3 hours after the end of cardiopulmonary bypass grafting (CPB). Outcomes were assessed by means of the kind, dosage, and duration of inotropic drug use during the postoperative period, lactate concentrations, and the duration of mechanical ventilation.

Results

Preoperative levels of NT-proBNP were significantly increased irrespective of the type of congenital heart defect and the age of the patient. Preoperative NT-proBNP levels were higher in patients receiving prolonged postoperative inotropic drug therapy (r = 0.56, P = .0003). By means of multivariate analysis with the duration of inotropic therapy as the dependent variable, a significant impact of preoperative NT-proBNP levels, the presence of a cyanotic heart defect, the risk adjustment for congenital heart surgery score, duration of CPB time, and postoperative lactate levels were demonstrated (R squared = 76.8%, P <.0001).

Conclusion

Preoperative NT-proBNP levels were associated with complicated postoperative outcome in children who underwent low-risk open-heart surgery. This marker may therefore be a useful tool in risk stratification of patients with congenital heart defects.

Abbreviations:  ANP, Atrial natriuretic peptides , BNP, Brain natriuretic peptide , CPB, Cardiopulmonary bypass grafting , NT-proBNP, N-terminal pro-brain natriuretic peptide , RACHS-1, Risk adjustment for congenital heart surgery , TnT, Troponin T