Predictive value of B-type natriuretic peptide level on the postoperative course of infants with congenital heart disease.

ABSTRACT

BACKGROUND: B-type natriuretic peptide (BNP) has been shown to have prognostic value for morbidity and mortality after cardiac surgery. Less is known about its prognostic value in infants. OBJECTIVES: To investigate the predictive value of BNP levels regarding the severity of the postoperative course in infants undergoing surgical repair of congenital heart disease. METHODS: We conducted a prospective comparative study. Plasma BNP levels in infants aged 1-12 months with congenital heart disease undergoing complete repair were measured preoperatively and 8, 24 and 48 hours postoperatively. Demographic and clinical data included postoperative inotropic support and lactate level, duration of mechanical ventilation, intensive care unit (ICU) and hospitalization stay. RESULTS: Cardiac surgery was performed in 19 infants aged 1-12 months. Preoperative BNP level above 170 pg/ml had a positive predictive value of 100% for inotropic score > or = 7.5 at 24 hours (specificity 100%, sensitivity 57%) and 48 hours (specificity 100%, sensitivity 100%), and was associated with longer ICU stay (P = 0.05) and a trend for longer mechanical ventilation (P = 0.12). Similar findings were found for 8 hours postoperative BNP above 1720 pg/ml. BNP level did not correlate with measured fractional shortening. CONCLUSIONS: In infants undergoing heart surgery, preoperative and 8 hour BNP levels were predictive of inotropic support and longer ICU stay. These findings may have implications for preplanning ICU loads in clinical practice. Further studies with larger samples are needed.