title: Prognostic value of biomarkers during and after non-ST-segment elevation acute coronary syndrome.
abstract: OBJECTIVE
  The aim of this study was to assess risk prediction by different biomarkers in patients with an ongoing non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and after clinical stabilization.
  
  
  BACKGROUND
  Different biomarkers reflect different aspects of the pathobiology in NSTE-ACS. However, there is little information regarding their relative prognostic value during the time course of disease.
  
  
  METHODS
  The N-terminal pro-brain natriuretic peptide (NT-proBNP), C-reactive protein (CRP), cardiac troponin I (cTnI), and the estimated glomerular filtration rate (eGFR) were measured at randomization and after 6 weeks and 6 months in 877 NSTE-ACS patients included in the FRISC (FRagmin and fast revascularization during InStability in Coronary artery disease) II trial. The biomarkers' prognostic value during 5-year follow-up was evaluated by Cox regression models, calculation of the c-statistics, and estimation of the net reclassification improvement (NRI).
  
  
  RESULTS
  Among the biomarkers measured at randomization, NT-proBNP was the strongest predictor for mortality (adjusted hazard ratio [HR]: 1.7; 95% confidence interval [CI]: 1.3 to 2.1; p < 0.001). Even during follow-up, NT-proBNP demonstrated the strongest association to the composite end point of death/myocardial infarction (adjusted HR at 6 weeks: 1.5; 95% CI: 1.3 to 1.7; p < 0.001; adjusted HR at 6 months: 1.4; 95% CI: 1.2 to 1.7; p = 0.001). Even CRP was independently predictive at 6 months for the composite end point (adjusted HR: 1.3; 95% CI: 1.1 to 1.5; p = 0.003). Only 6-week results of NT-proBNP provided significant incremental prognostic value to established risk indicators regarding the composite end point (c-statistics 0.69 [p = 0.03]; NRI 0.11 [p = 0.03]).
  
  
  CONCLUSIONS
  The NT-proBNP is an independent risk predictor in patients with ongoing NSTE-ACS and after clinical stabilization. The CRP exhibits increasing predictive value at later measurements. However, only NT-proBNP provided incremental prognostic value and might therefore be considered as a complement for early follow-up controls after NSTE-ACS.
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University Hospital and Uppsala Clinical Research Centre, Uppsala, Sweden. kai.eggers@ucr.uu.se
authors.forename: Kai M
authors.initials: KM
authors.lastname: Eggers
authors.forename: Bo
authors.initials: B
authors.lastname: Lagerqvist
authors.forename: Per
authors.initials: P
authors.lastname: Venge
authors.forename: Lars
authors.initials: L
authors.lastname: Wallentin
authors.forename: Bertil
authors.initials: B
authors.lastname: Lindahl
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D019210:Troponin I / Q000097:blood
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein