Intra-individual variability in troponin T concentration in dialysis patients

PURPOSE: Haemodialysis patients often have increased TnT concentrations in the absence of symptoms suggestive of acute coronary syndrome. To evaluate the potential usefulness of establishing patient specific baselines, we investigated intra-individual variability of TnT concentration in stable haemodialysis patients. METHODS: We measured pre-dialysis troponin T concentrations weekly for 15 weeks in 61 stable haemodialysis patients. RESULTS: Thirty two of 61 patients had at least one result greater than the diagnostic cut-off for significant myocardial damage of 0.04 microg/L. The intra-individual variability was small; 99% of all the variance from each patient's median was < or = 0.063 microg/L. CONCLUSIONS: Intra-individual variability in TnT concentration is small enough to merit establishment a of baseline concentration for each haemodialysis patient. This baseline is stable over at least 15 weeks; samples need be collected no more frequently than this. A change in concentration of more than 0.06 microg/L from the individual's baseline is significant.