title: Troponin T and N-terminal pro B-Type natriuretic peptide and presence of coronary artery disease.
abstract: BACKGROUND
  We tested the effects of exercise intensity, sampling intervals, degree of coronary artery stenosis, and demographic factors on circulating N-terminal pro B-Type natriuretic peptide (NT-pro-BNP) and cardiac Troponin T (cTnT) in subjects suspected of coronary artery disease (CAD).
  
  
  METHODS
  A total of 242 subjects referred for diagnostic evaluation of possible CAD had blood samples obtained before, 5 min after, and again 20 h after a symptom-limited exercise test.
  
  
  RESULTS
  Totally 40 subjects had CAD with ≥ 50% stenosis, 115 subjects had no stenosis and 87 subjects served as controls. In univariate analysis CAD-subjects had higher median baseline NT-pro-BNP-levels (85.3 ng/L) compared with non-CAD-subjects (41.3 ng/L) and controls (40.1 ng/L), both p < 0.001, but the association disappeared in multivariate analysis adjusted for age and gender. NT-pro-BNP increased similarly after exercise in CAD-subjects, non-CAD-subjects, and controls (median increase 8.14 ng/L) and the increase was positively associated with baseline NT-pro-BNP but not presence of CAD. Median baseline cTnT was 6.25 ng/L in CAD-subjects and 3.00 ng/L in non-CAD-subjects as well as controls, both p < 0.0001. Median ΔcTnT (baseline to 20 h after exercise) was higher in CAD-subjects than non-CAD-subjects and controls (0.62 ng/L vs. 0.0 ng/L, p < 0.001). A linear relationship between ΔcTnT and 'percent of predicted maximal heart rate achieved' was found in subjects with ≥ 70% stenosis (n = 24, r = 0.4067 p = 0.046).
  
  
  CONCLUSIONS
  Baseline cTnT and ΔcTnT were found to be independently associated with CAD and also with exercise intensity in stable chest pain subjects. These properties were not identified for NT-pro-BNP.
authors: Department of Cardiology, Copenhagen University Hospital of Bispebjerg , Bispebjerg Bakke, Copenhagen NV , Denmark.
authors: Mette R
authors: MR
authors: Mouridsen
authors: Ahmad
authors: A
authors: Sajadieh
authors: Christian M
authors: CM
authors: Carlsen
authors: Nick
authors: N
authors: Mattsson
authors: Merete
authors: M
authors: Heitmann
authors: Olav W
authors: OW
authors: Nielsen
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood* / Q000000981:diagnostic imaging; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D020107:Troponin T / Q000097:blood*; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain
keywords: Angina pectoris; atherosclerosis; biological markers; exercise test; troponin