Cardiac troponin T and I in end-stage renal failure

Background: In patients suffering from end-stage renal failure, cardiac tro ponin T (cTnT) and I (cTnI) may be increased in serum without other signs o f acute myocardial damage. Whether these increases are specific to myocardi al injury or nonspecific is not completely clear. Methods: We investigated time courses of cTnT and cTnI over 1 year and the clinical outcome over 2 years in 59 patients with end-stage renal failure u ndergoing chronic hemodialysis. At the start of the study, we divided the p atients into two groups, group 1, without history of cardiac failure, and g roup 2,with history of cardiac failure, and looked for differences between the groups in later adverse outcome. cTnT was measured using the Enzymun(R) troponin T assay on an ES 700 analyzer (Roche). cTnI was measured on a Str atus(R) II analyzer (Dade Behring). Creatinine and blood urea nitrogen were measured on a Vitros(R) 950 IRC (Ortho). Results: Dialysis acutely increased cTnT (P < 0.01) and decreased cTnI (P < 0.001) regardless of the dialysis membrane used. Although statistically no t significant, cTnT but not cTnI was increased more frequently in group 2 t han in group 1, in some cases over the whole study period. Five patients (8 .5%) died of cardiac complications within 2 years; all of them had mostly i ncreased cTnT and, in one or more samples, increased cTnI. Conclusions: Dialysis alters measured cTnT and cTnI concentrations in serum . In patients suffering from end-stage renal failure, sporadic or persisten tly increased cTnT and cTnI appear to predict cardiac complications. Becaus e of the effects of the dialysis procedure on troponin values, we recommend that blood be collected before dialysis. (C) 2000 American Association for Clinical Chemistry.