B-type natriuretic peptide and C-terminal-pro-endothelin-1 for the prediction of severely impaired peak oxygen consumption.

Objective: To assess the utility of B-type natriuretic peptide (BNP) and C-terminal-pro-endothelin-1 (CT-proET-1) to predict a severely impaired peak oxygen consumption (peak VO(2), < 14 mL kg(-1) min(-1)) in patients referred for cardiopulmonary exercise testing.

Design: Cross-sectional study.

Setting: Tertiary care center.

Methods: Peak VO(2), BNP and CT-proET-1 were assessed in 141 consecutive patients referred for cardiopulmonary exercise testing.

Results: B-type natriuretic peptide [median (interquartile range) 48 (38-319) vs. 33 (15-86) pg mL(-1); P = 0.002] and CT-proET-1 [87 (76-95) vs. 60 (52-74) pmol L(-1); P < 0.001] were higher in patients with a peak VO(2) < 14 mL kg(-1) min(-1) (n = 30) than in those with a peak VO(2) > or = 14 mL kg(-1) min(-1) (n = 111). CT-pro-ET-1 had a higher area under the receiver-operator-characteristics curve (AUC) to predict a peak VO(2) < 14 mL kg(-1) min(-1) than BNP (0.79 vs. 0.68; P = 0.04). The optimal BNP cut-off of 37.2 pg mL(-1) had a sensitivity of 80% and a specificity of 56%. The optimal CT-proET-1 cut-off of 74.4 pmol L(-1) had a sensitivity of 80% and specificity of 76%. A five-item score composed of body mass index, diabetes, forced expiratory volume within the first second, alveolo-arterial oxygen pressure difference, and BNP had an AUC of 0.88 to predict a peak VO(2) < 14 mL kg(-1) min(-1). Adding CT-proET-1 to the score resulted in an AUC of 0.92.

Conclusions: C-terminal-pro-endothelin-1 is superior to BNP for the prediction of a peak VO(2) < 14 mL kg(-1) min(-1) in patients referred for CPET. A score incorporating body mass index, diabetes status, spirometry, blood gases, BNP and CT-proET-1 improves the prediction of a peak VO(2) < 14 mL kg(-1) min(-1) based on single biomarkers.