title: Impact of kidney function on plasma troponin concentrations after coronary artery bypass grafting.
abstract: BACKGROUND
  To date, there have been no studies reliably showing an influence of the kidney on the concentration of troponins. We therefore analysed the concentration curves in patients after coronary artery bypass grafting (CABG) according to their dependence on renal function.
  
  
  METHODS
  We determined cardiac troponin I (cTnI), cardiac troponin T (cTnT) and creatinine in plasma in 28 patients after CABG. Discrimination into patients with normal (n=13) and impaired (n=15) renal function was based on creatinine clearance (Crea-Clear). The curves for cTnI and cTnT, as recorded by post-operative measurements, were approximated using mathematical functions. The curve parameters peak maximum (P(max)), peak position (P(pos)), half-height breadth (HHB) and area under the curve (AUC) were established after this. Assuming an exponential function, the half-life (t(1/2)) of cTnI was determined from the declining part of the curve.
  
  
  RESULTS
  For both, cTnI and cTnT, significant differences in P(max), P(pos), HHB and AUC were detected after curve approximation. The t(1/2) values of cTnI were 25.1 h (22.0-35.3) for the group with normal renal function and 38.4 h (35.9-51.9) for patients with impaired renal function (P=0.001). An influence of diabetes mellitus (Dm), renal replacement therapy or the age of the patients could not be verified.
  
  
  CONCLUSIONS
  The results of this study clearly demonstrate that kidney function has an impact on plasma troponin concentrations. In everyday clinical practice this has to be considered when interpreting elevated plasma troponin concentration in patients with impaired renal function.
authors: Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Zentralinstitut für Laboratoriumsmedizin und Pathobiochemie, Charité-Platz 1, 10117 Berlin, Germany.
authors: Regine
authors: R
authors: Wiessner
authors: Kurt
authors: K
authors: Hannemann-Pohl
authors: Reinhard
authors: R
authors: Ziebig
authors: Herko
authors: H
authors: Grubitzsch
authors: Berthold
authors: B
authors: Hocher
authors: Ortrud
authors: O
authors: Vargas-Hein
authors: Andreas
authors: A
authors: Lun
authors: Ingolf
authors: I
authors: Schimke
authors: Lutz
authors: L
authors: Liefeldt
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D007668:Kidney / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019210:Troponin I / Q000097:blood*; D020107:Troponin T / Q000097:blood*
chemical_list: D019210:Troponin I; D020107:Troponin T