Sources of variability in measurements of cardiac troponin T in a community-based sample: the atherosclerosis risk in communities study.

Author(s): Agarwal SK, Avery CL, Ballantyne CM, Catellier D, Nambi V, Saunders J, Sharrett AR, Coresh J, Heiss G, Hoogeveen RC

Publication: Clin Chem, 2011, Vol. 57, Page 891-7

PubMed ID: 21519038 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of intraindividual variability, repeated sampling, and frozen storage on plasma cTnT levels. Plasma was stored at -70 degrees C and shipped at weekly intervals, under unspecified conditions, to a central lab where it was stored at -70 degrees C for up to 8 years. In some cases multiple specimens were collected from a single venipuncture and handled individually, but in other cases the plasma was aliquoted at first analysis and then stored for less than 2 days prior to repeat analysis. Specimens from the same individual were acquired 4-8 weeks and 8 years after the initial specimen.

   Summary of Findings:

   Specimens taken from the same individual 4-8 weeks apart had a CV of 16.6%, but replicate specimens from the same venipuncture that were mailed and processed separately had a CV of 18.3%. In contrast, the intraindividual variability between specimens obtained (and stored) 8 years apart was 48.4%, and only a weak correlation of values was observed (r=0.36). In specimens collected and stored for 36 months, cTnT levels declined by an average of 0.36 ng/L during the first year. cTnT levels were approximately 3-fold higher in individuals with heart failure than those without. Repeated assaying of the same specimen 2 days later gave a CV of 2.1% in individuals with heart failure and 11.2% in those without.

   Biospecimens

   • Bodily Fluid - Plasma
   • Bodily Fluid - Blood

   Preservative Types

   • Frozen

   Diagnoses:

   • Cardiovascular Disease
   • Not specified

   Platform:

   Analyte	Technology Platform
   Protein	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	0-3 years 0 days 2 days 4-8 weeks 8 years
   Biospecimen Acquisition	Time of biospecimen collection	Day 0 4-8 weeks later 8 years later
   Preaquisition	Diagnosis/ patient condition	Heart failure No heart failure

   View more