title: Prognostic value of circulating amino-terminal pro-C-type natriuretic peptide in critically ill patients.
abstract: BACKGROUND
  C-type natriuretic peptide (CNP) is a paracrine molecule which is mainly synthesized in the vasculature. High levels have been reported in sepsis, and CNP has been proposed as a biomarker predicting sepsis in traumatized patients. We aimed at evaluating the diagnostic and prognostic value of N-terminal pro-CNP (NT-proCNP) for predicting sepsis, disease severity and mortality in critically ill medical patients.
  
  
  METHODS
  273 critically ill patients (197 patients with sepsis or septic shock, 76 without evidence of sepsis) and 43 healthy controls were consecutively included in a prospective clinical single-center non-interventional study at the Medical Intensive Care Unit, RWTH-University Aachen, Germany. Patients' outcome was followed for about 1 year. NT-proCNP serum concentrations were determined upon ICU admission, as well as in the mornings of day 3 and day 7 after admission. Intensive care treatment measures as well as routine and experimental laboratory parameters were recorded and analyzed.
  
  
  RESULTS
  NT-proCNP serum concentrations upon admission to the ICU were elevated in critically ill patients as compared with healthy controls. Patients with sepsis had significantly higher NT-proCNP levels than non-sepsis patients. NT-proCNP was strongly associated with inflammatory parameters (i.e. C-reactive protein, procalcitonin and TNF-α), biomarkers of organ dysfunction and clinical composite scores (APACHE-II, SOFA, SAPS2). NT-proCNP levels at admission and day 3 were found to be a strong predictive marker for ICU- and overall survival. Moreover, a decline of serum NT-proCNP after admission to the ICU was associated with reduced mortality. The predictive power of serum NT-proCNP was similar to 'conventional' prognostic tools such as clinical scores.
  
  
  CONCLUSIONS
  NT-proCNP is significantly elevated in critically ill patients, with highest levels in sepsis. Inflammation as well as organ function are strongly associated with NT-proCNP serum concentrations. Low initial NT-proCNP levels and a decline during initial treatment indicate a favourable ICU- and long-term outcome.
authors.affiliation: Department of Medicine III, RWTH-University Hospital Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany. frank.tacke@gmx.net
authors.forename: Alexander
authors.initials: A
authors.lastname: Koch
authors.forename: Sebastian
authors.initials: S
authors.lastname: Voigt
authors.forename: Edouard
authors.initials: E
authors.lastname: Sanson
authors.forename: Hanna
authors.initials: H
authors.lastname: Dückers
authors.forename: Andreas
authors.initials: A
authors.lastname: Horn
authors.forename: Henning W
authors.initials: HW
authors.lastname: Zimmermann
authors.forename: Christian
authors.initials: C
authors.lastname: Trautwein
authors.forename: Frank
authors.initials: F
authors.lastname: Tacke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016638:Critical Illness; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D020098:Natriuretic Peptide, C-Type / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018805:Sepsis / Q000097:blood* / Q000401:mortality / Q000628:therapy*; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D020098:Natriuretic Peptide, C-Type