Current markers of myocardial injury lack specificity in patients with end-stage renal disease (ESRD). In particular, a false positive creatine kinase-MB (CKMB) elevation occurs in 5–10% of patients with ESRD. The aim of this study was to ascertain the relationship between CKMB and cardiac troponin I (cTnl), a new, highly sensitive and specific marker for myocardial injury, in the authors' dialysis population and compare their specificities. Blood samples were obtained from 112 dialysis patients (35 in peritoneal dialysis; 77 in hemodialysis). Patients were asymptomatic for cardiac ischemia and skeletal muscle injury. Mean ± SD CKMB mass was 3.16 ± 2.26 µg/L (range, 0.34–13.62), and cTnl was 0.025 ± 0.061 ng/ml (range, 0.001–0.496). CKMB and cTnl levels did not correlate (r2=0.002; p=0.61). CKMB mass concentration was significantly higher in men and in diabetics. No patient had a cTnl level greater than 1.5 µg/l, and eight asymptomatic patients had a CKMB mass greater than 6.7 µg/L. These data suggest a specificity of 100% for cTnl vs 94.6% for CKMB at these cutoff values. It is suggested that cTnl replace CKMB as a marker of myocardial injury in patients with ESRD.
Copyright © 1998 by the American Society for Artificial Internal Organs