Methods: A prospective cohort study was designed at the pediatric cardiac surgery clinic of our institution. This cross-sectional study included 20 patients (13 boys, 7 girls; mean age 9.2±4.3 months; range, 4 to 18 months) who underwent ventricular septal defect repair between February 2012 and September 2012. Blood samples were taken at baseline before surgery, followed by six sampling at different time points during the postoperative course.

Results: In-hospital mortality was 5%. The mean preoperative B-type natriuretic peptide levels were significantly correlated with the preoperative mean pulmonary artery pressure (p<0.001). The mean B-type natriuretic peptide levels showed a great postoperative variation (mean±SD: 980.05±1125.38). The preoperative B-type natriuretic peptide values were significantly correlated with postoperative values at each time point. The correlation between intra-individual B-type natriuretic peptide, the mean and increased inotrope scores, prolonged time to extubation, and prolonged intensive care unit stay was under the limit of significance (p>0.05), whereas intra-individual B-type natriuretic peptide standard deviation was correlated with longer times of intensive care unit stay (p<0.003).

Conclusion: High intra-individual variability in serial measurements of B-type natriuretic peptide may be potentially a predictor of adverse outcomes following ventricular septal repair.