title: Prognostic comparison of different sensitivity cardiac troponin assays in stable heart failure.
abstract: BACKGROUND
  Cardiac troponin (cTn) levels offer prognostic information for patients with heart failure. Highly sensitive assays detect levels of cTn much lower than the 99th percentile of standard cTn assays. We hypothesize that cardiac troponin levels measured by a high-sensitivity assay provide better prognostic value compared with cTn levels measured by a standard assay in patients with chronic heart failure.
  
  
  METHODS
  We measured high-sensitivity cTnT (hs-cTnT) and standard cardiac troponin I (cTnI) levels, as well as amino-terminal pro B-type natriuretic peptide (NT-proBNP) in 504 sequential stable patients with a history of heart failure who underwent elective coronary angiography, without acute coronary syndrome, and with 5-year follow-up of all-cause mortality.
  
  
  RESULTS
  The median hs-cTnT level was 21.2 (interquartile range 12.3-40.9) ng/L and 170 subjects died over 5 years. In a head-to-head overall comparison, hs-cTnT provided increased prognostic utility compared with cTnI (area under the curve [AUC] 66.1% and AUC 69.4%, respectively, P = .03; 9.0% integrated discrimination improvement, P < .001; and 13.6% event-specific reclassification, P < .001), and was independent of NT-proBNP and renal function. Even within the subset of patients where cTn levels by both assays were above the limit of quantification, higher hs-cTnT is associated with a 2-fold increase in 5-year mortality risk after adjusting for traditional risk factors (tertile 1 vs 3: hazard ratio [95% confidence interval] 2.0 [1.3-3.2]; P = .0002).
  
  
  CONCLUSIONS
  Cardiac troponin can be detected by the high-sensitivity assay in more patients with chronic heart failure than the standard assay, and may yield independent and better prognostic accuracy for mortality prediction than standard assay.
authors.affiliation: Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Justin L
authors.initials: JL
authors.lastname: Grodin
authors.affiliation: Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Sarah
authors.initials: S
authors.lastname: Neale
authors.affiliation: Department of Mathematics, Cleveland State University, Cleveland, Ohio.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio; Department for Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Stanley L
authors.initials: SL
authors.lastname: Hazen
authors.affiliation: Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio; Department for Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio. Electronic address: tangw@ccf.org.
authors.forename: W H Wilson
authors.initials: WH
authors.lastname: Tang
mesh_terms: D000368:Aged; D019540:Area Under Curve; D002908:Chronic Disease; D016001:Confidence Intervals; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D007677:Kidney Function Tests / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000008:administration & dosage* / Q000097:blood; D009820:Ohio / Q000453:epidemiology; D062072:Patient Acuity; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000097:blood; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014336:Troponin / Q000032:analysis / Q000097:blood
chemical_list: D010446:Peptide Fragments; D014336:Troponin; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain
keywords: Cardiac troponin; Heart failure; High-sensitivity cardiac troponin; Prognosis