Levels of N-terminal-pro-brain natriuretic peptide in congenital heart disease surgery and its value as a predictive biomarker.

OBJECTIVES: To explore the value of N-terminal-pro-brain natriuretic peptide (NT-ProBNP) as a predictive biomarker of postoperative cardiovascular surgery. METHODS: A prospective study of 68 patients (0-15 years), submitted to open-heart surgery was conducted. NT-ProBNP and other biochemical and clinical markers were measured preoperatively and during the first 48 postoperative hours. RESULTS: NT-ProBNP preoperative reduced one hour after surgery, increased significantly later, and remained without change between 12 hours and 48 hours postoperatively. Peak values (24 hours) were correlated with preoperative levels (R=0.73; P<0.001), risk adjustment congenital heart surgery-1 (R=0.37; P<0.002), length of cardiopulmonary bypass (CPB) (R=0.57; P<0.001); age (R=-0.55; P<0.001) and weight of patients (R=-0.46; P<0.001). Independent predictors of NT-ProBNP-peak were preoperative value (β=0.42) and CPB length (β=0.24; R(2) of model 0.63; P<0.001). The peak values were correlated to a maximum inotropic score (R=0.46; P<0.001), duration of inotropic therapy (R=0.44; P<0.001), duration of mechanical ventilation support (R=0.39; P<0.001) and length of stay in the Pediatric Intensive Care Unit (R=0.45; P<0.001). Independent predictors of enhanced intensive care unit stay, controlling by risk adjustment score, were high preoperative NT-ProBNP (OR 5.5, 95% CI 1.2-25.5), and high postoperative troponine (OR 10.5, 95% CI 2.2-49.2). CONCLUSIONS: NT-ProBNP concentration is dependent on time during the perioperative period, it peaks at 24 hours and depends on the preoperative value and CPB length. A high peptide level before surgery is an independent predictor of prolonged stay in intensive pediatric care.