title: Biological variation of cardiac troponin T in patients with end-stage renal disease and in healthy individuals.
abstract: BACKGROUND
  Serum cardiac troponin T concentrations are important predictors of cardiovascular and all-cause mortality in end-stage renal disease. In patients with end-stage renal disease, assessment of serial results is essential to distinguish between a cardiovascular event and chronic elevation. We employed a high-sensitivity serum cardiac troponin T assay to evaluate the long-term biological variation in end-stage renal disease patients and in healthy individuals; these biological variation data were used to define the reference change value and the analytical goals.
  
  
  METHODS
  Serum samples were collected from 18 end-stage renal disease patients in steady-state conditions, one per month for 6 months, and from 11 healthy volunteers at weekly intervals over 5 weeks. Biological variation data were derived using analysis of variance.
  
  
  RESULTS
  Baseline serum cardiac troponin T concentrations in end-stage renal disease patients were above the 99th percentile of the healthy population and increased with duration of haemodialysis. For end-stage renal disease patients, within-subject (CVI) and between-subject (CVG) coefficients of variation were 14.7 and 77.8%, respectively, whereas these were 5.9 and 30.4%, respectively, for healthy individuals. The derived two-tailed and one-tailed reference change values were 44.1 and 37.1%, respectively, for end-stage renal disease patients, and 21.6 and 18.2% for healthy subjects.
  
  
  CONCLUSIONS
  For appropriate clinical management of end-stage renal disease patients in the context of a cardiovascular event, regular monitoring of serum cardiac troponin T concentrations could be important in order to allow future comparison through reference change value. Biological variation data in end-stage renal disease patients were significantly higher than for healthy individuals; therefore, the use of proper reference change value data is recommended. Moreover, the observed CVI values provide demanding imprecision goals for current technology.
authors.affiliation: Service of Biochemistry, Hospital San Agustín, Avilés, Principado de Asturias, Spain.
authors.forename: Zoraida
authors.initials: Z
authors.lastname: Corte
authors.affiliation: Service of Nephrology, Hospital San Agustín, Avilés, Principado de Asturias, Spain.
authors.forename: Camino
authors.initials: C
authors.lastname: García
authors.affiliation: Service of Biochemistry, Hospital San Agustín, Avilés, Principado de Asturias, Spain Department of Biochemistry and Molecular Biology. University of Oviedo, Principado de Asturias, Spain rafael.venta@sespa.princast.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Venta
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood* / Q000150:complications / Q000503:physiopathology / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D006435:Renal Dialysis; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: Analytical quality specifications; biological variation; cardiovascular disease; chronic renal disease; high-sensitivity cardiac troponin T