Proatrial natriuretic peptide is a better predictor of 28-day mortality in septic shock patients than proendothelin-1

Background: Septic shock is a major health care problem that affects a heterogeneous population of patients. To improve sepsis management, a key point is to decrease this heterogeneity by stratifying patients according to specific criteria, such as appropriate biomarkers. As the early phase of septic shock is characterized by cardiovascular dysfunction, precursors of vasoactive hormones represent interesting candidates. The objective of the present study was to concomitantly assess the predictive value of C-terminal proendothelin-1 and midregional proatrial natriuretic peptide (CT-proET-1 and MR-proANP, respectively vasoconstrictor and vasodilator) on 28-day mortality following septic shock. Methods: In this observational study which included 99 patients, concentrations of MR-proANP and CT-proET-1 were measured using an immunoluminometric assay three times within the first week after the onset of septic shock. Results: While MR-proANP concentrations were significantly increased in non-survivors in comparison with survivors, no differences were noted for CT-proET-1. Increased MR-proANP concentrations were significantly associated with mortality after both univariate and multivariate analyses, adjusted for usual clinical confounders [SAPS II (simplified acute physiology score II), SOFA (sepsis-related organ failure assessment) scores and number of co-morbidities]. Conclusions: In septic shock patients, MR-proANP appears to be a good predictor of 28-day mortality, whereas CT-proET-1 does not present any predictive value during monitoring. Clin Chem Lab Med 2010; 48:1813-20.