Natriuretic peptides for the prediction of severely impaired peak VO2 in patients with lung disease.

Background: B-type natriuretic peptide (BNP) is a predictor of death in patients with lung disease. We hypothesised that in patients with lung disease, BNP and N-terminal-pro-B-type natriuretic peptide (NT-proBNP) could predict a peak VO(2)<15 ml/kg/min, which is the proposed cut-off indicating an increased risk of perioperative complications during lung resection surgery.

Methods: BNP and NT-proBNP were measured in 85 patients with a variety of pulmonary pathologies undergoing cardiopulmonary exercise testing and fulfilling criteria for appropriate effort.

Results: BNP [69 (42-270) vs. 33 (15-65)pg/ml; p=0.001] and NT-proBNP [290 (129-1075) vs. 65 (21-129)pg/ml; p<0.001] were higher in patients with peak VO(2)<15 ml/kg/min (n=27) as compared to those with peak VO(2)> or =15 ml/kg/min (n=58). Apart from the forced expiratory volume within the first second (FEV(1)), body mass index (BMI), diabetes, and the alveolo-arterial oxygen pressure difference [D(A-a)O(2); only in the BNP model], BNP or NT-proBNP respectively were independent predictors of peak VO(2)<15 ml/kg/min. The areas under the receiver-operator-characteristics curve (AUC) for BNP and NT-proBNP to predict a peak VO(2)<15 ml/kg/min were 0.73 and 0.80 respectively. A five-item (BNP) or four-item (NT-proBNP) score including BMI, FEV(1), diabetes, D(A-a)O(2), and BNP/NT-proBNP had an AUC of 0.87 and 0.88 respectively for the prediction of peak VO(2)<15ml/kg/min.

Conclusions: In patients with lung disease, BNP or NT-proBNP is independently associated with low peak VO(2). A simple score based on spirometry, blood gases and BNP or NT-proBNP has a high accuracy for the prediction of a peak VO(2)<15 ml/kg/min.