Serum troponin T measurement in patients with chronic renal impairment predicts survival and vascular disease: a 2 year prospective study

Background. Cardiovascular mortality in end-stage renal failure patients is high and early risk stratification in these patients may aid clinical management improving outcomes. Cardiac troponin T (cTnT) is a component of the cardiac myocyte which is released into the circulation following myocardial necrosis. It has been shown to be of prognostic significance in patients with unstable angina. The role of cTnT in patients with renal disease remains unclear. The aim of this investigation, therefore, was to assess the prognostic significance of cTnT in chronic renal impairment patients, pre-dialysis. Methods. Ninety-six patients with chronic renal impairment were followed prospectively after cTnT determination by a quantitative laboratory method. The clinical outcomes after 2 years were determined. The measured cTnT values were correlated with biochemical parameters and clinical end-points. Results. A cut-off of 0.1 ng/ml was used in assessing the prognostic significance of cTnT. Twenty-five patients had a cTnT > 0.1 ng/ml, whilst 71 had a cTnT less than or equal to0.1 ng/ml. Twenty-one patients died during the follow-up period. Eleven of these had elevated cTnT at entry into the study. Death rate in the patients with cTnT > 0.1 ng/ml was 42% compared with 14% in those with levels below the cut-off. Thirty-three patients died or had a vascular event. The rate of death or a vascular event in the elevated group was 64% compared with 24% in those with levels below the cut-off. At the end of the study, 23 patients were treated by continuous ambulatory peritoneal dialysis, 29 by haemodialysis, 22 had functioning renal transplants and one patient was not on renal replacement therapy. Factors that were found to significantly affect cTnT were diabetes, age and urea. cTnT was found to be a significant predictor of survival in these patients. Patients with high cTnT values were more likely to end up on haemodialysis. No relation of renal function to cTnT level was found. Conclusions. These results show that in patients with renal impairment, the measurement of cTnT prior to commencing renal replacement is a significant independent predictor of survival. cTnT did show potential as a prognostic test to stratify patients with a high cardiovascular risk and may enable intensive risk factor modification in this patient group. This may be of further use in selection of patients' suitability for renal transplantation.