Midregional pro-A-type natriuretic peptide and carboxy-terminal provasopressin may predict prognosis in community-acquired pneumonia

Abstract

Background: Markers to better assess severity of disease in patients with community-acquired pneumonia (CAP) would help improve medical care of this condition. The hemodynamic biomarkers carboxy-terminal provasopressin (CT-proAVP; copeptin) and midregional proatrial natriuretic peptide (MR-proANP) are increased under septic conditions, in which MR-proANP has been described as a prognostic predictor. We aimed to explore the diagnostic accuracy of MR-proANP and CT-proAVP to predict mortality in patients with CAP. Methods: We conducted a prospective observational study of patients with CAP. We measured biomarkers in serum samples obtained at diagnosis and performed univariate and multivariate analyses to identify potential predictors of mortality. Results: CT-proAVP and MR-proANP concentrations were measured in 173 patients. We found a positive correlation between pneumonia severity index (PSI) and MR-proANP (rs = 0.68, P <0.0001) and between PSI and CT-proAVP (rs = 0.44, P <0.0001). Median (interquartile range) CT-proAVP and MR-proANP values were 8.2 (5.3-16.8) and 73.6 (44.6-144.0) pmol/L, respectively. Nonsurvivors had significantly higher MR-proANP and CT-proAVP than survivors (median 259.0 vs 71.8 pmol/L, P = 0.01, and 24.9 vs 8.1 pmol/L, P = 0.03, respectively). In multivariate analysis including PSI, procalcitonin, C-reactive protein, lipopolysaccharide-binding protein, CT-proAVP, and MR-proANP concentrations, only CT-proAVP remained an independent predictor of death (odds ratio 1.05, P = 0.007). Cutoff values of >18.9 pmol/L for CT-proAVP and >227 pmol/L for MR-proANP showed the highest diagnostic accuracy to predict mortality. Conclusions: CT-proAVP and MR-proANP may be used to predict prognosis in patients with CAP. © 2007 American Association for Clinical Chemistry.