Brain natriuretic peptide levels before and after ventricular septal defect repair.

BACKGROUND

Brain natriuretic peptide is a relatively recently discovered circulating mediator that has been correlated with the degree of heart failure in adults. This study evaluated the preoperative and postoperative brain natriuretic peptide levels in infants and children undergoing ventricular septal defect repair.

METHODS

The study enrolled 18 infants and children (ages 2 months to 15.6 years) scheduled for surgical repair of their ventricular septal defects. Brain natriuretic peptide levels were drawn preoperatively and then postoperatively at 1, 24, 48, and 72 hours. The amount of shunt (the ratio of pulmonary blood flow [Q(p)]/systemic blood flow [Q(s)]) through the ventricular septal defect was determined by saturation levels performed in the catheterization laboratory or intraoperatively.

RESULTS

The preoperative brain natriuretic peptide levels (pg/mL) averaged 78 +/- 57, and the postoperative levels were 168 +/- 241 at 1 hour, 418 +/- 330 at 24 hours, 405 +/- 364 at 48 hours, and 391 +/- 397 at 72 hours. These differences were significant for each postoperative time point compared with preoperative values. Preoperative brain natriuretic peptide and the Q(p)/Q(s) were significantly correlated (age-adjusted R(2) = 0.33, p < 0.001).

CONCLUSIONS

Brain natriuretic peptide levels have a close correlation with the physiologic volume load caused by ventricular septal defects. The preoperative brain natriuretic peptide levels were also found to be predictive for the postoperative time course of brain natriuretic peptide level changes. These results suggest that brain natriuretic peptide levels may be a useful clinical marker in infants and children with ventricular septal defects.