Predictive value of cardiac troponin I and T for subsequent death in end-stage renal disease

Abstract

Background: This study determined the prevalence of increased cardiac troponin I (cTnI) and T (cTnT) in end-stage renal disease (ESRD) patients and whether an increased troponin was predictive of death.

Methods and results: Serum was obtained from 733 ESRD patients and measured for cTnI and cTnT. Relative risks were estimated using Cox proportional hazards regressions univariately and adjusted for age, time on dialysis, and coronary artery disease. Kaplan-Meier curves compared time to event data between groups. Greater percentages of patients had an increased cTnT versus cTnI at each cutoff, as follows: 99th percentile, 82% versus 6%; 10% coefficient of variation, 53% versus 1.0%; and receiver operator characteristic, 20% versus 0.4%. Increased versus normal cTnT was predictive of increased mortality using all cutoffs and only above the 99th percentile for cTnI. Two-year cumulative mortality rates increased (P<0.001) with changes in cTnT from normal (<0.01 microg/L, 8.4%) to small (> or =0.01 to <0.04 microg/L, 26%), moderate (> or =0.04 to <0.1 microg/L, 39%), and large (> or =0.1 microg/L, 47%) increases. Two-year mortalities were 30% for cTnI <0.1 microg/L and 52% if > or =0.1 microg/L. Univariate and adjusted relative risks of death associated with elevated (>99th percentile) cTnT were 5.0 (CI, 2.5 to 10; P<0.001) and 3.9 (CI, 1.9 to7.9; P<0.001) and cTnI were 2.0 (CI, 1.3 to 3.3; P=0.008) and 2.1 (CI, 1.3 to 3.3; P=0.007). Age, coronary artery disease, and time on dialysis were also independent predictors of mortality.

Conclusions: Increases in cTnT and cTnI in ESRD patients show a 2- to 5-fold increase in mortality, with a greater number of patients having an increased cTnT.