title: Contribution of renal function impairment to unexplained troponin T elevations in congestive heart failure.
abstract: BACKGROUND
  Patients with severe congestive heart failure (CHF) often have unexplained elevations in serum concentrations of troponin T (TnT), and it is proposed that this is due to cardiac TnT release because of underlying cardiac disease. We investigated whether impaired renal function is an additional underlying phenomenon contributing to increased TnT levels in patients with CHF.
  
  
  METHODS
  Sixty-two patients with nonischemic CHF, New York Heart Association (NYHA) class III-IV, with normal coronary angiogram and normal serum creatinine were included in the study. Baseline glomerular filtration rate (GFR) was calculated using the Cockcroft Gault equation.
  
  
  RESULTS
  Although mean creatinine level was normal (0.92 +/- 0.17 mg/dL), mean GFR was low (56 +/- 16 mL/min) in the cohort. Elevated (>or=0.02 microg/L) TnT was measured in 33 patients (53%). Compared with patients with normal (<0.02 microg/L) TnT levels, patients with elevated TnT had significantly higher NYHA class (p = 0.02), longer duration of disease (p = 0.02), lower GFR (p = 0.0001), and lower LVEF (p = 0.0001). There were significant associations between TnT levels and duration of disease (r = 0.29, p = 0.01), creatinine (r = 0.30, p = 0.01), GFR (r = -0.55, p < 0.0001), and LVEF (r = -0.39, p = 0.001). Independence of these associations was evaluated in multiple linear regression analysis, and serum TnT was independently and negatively associated only with GFR (p = 0.005).
  
  
  CONCLUSIONS
  Renal function (GFR) correlated significantly and more strongly than cardiac function (LVEF) with the serum TnT levels in patients with CHF. This supports our hypothesis that impaired renal function causes the accumulation of troponin and is very likely the cause of unexplained elevations of serum TnT in patients severe CHF.
authors.affiliation: Gaziantep University, School of Medicine, Department of Biochemistry, Gaziantep, Turkey. naksoy@gantep.edu.tr
authors.forename: Nur
authors.initials: N
authors.lastname: Aksoy
authors.forename: Orhan
authors.initials: O
authors.lastname: Ozer
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Sari
authors.forename: Murat
authors.initials: M
authors.lastname: Sucu
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aksoy
authors.forename: Iclal
authors.initials: I
authors.lastname: Geyikli
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000503:physiopathology*; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T