Background: In patients with chronic renal failure undergoing long-term hemodialysis, ischemic heart disease accounts for up to 50% of mortality. Cardiac troponins T (TnT) and I (TnI) are frequently elevated in this patient group, but data on the prognostic relevance of these markers, especially TnI, are controversial. The aim of this study was to investigate the prognostic power of a new, sensitive TnI assay in comparison with TnT and other cardiac markers.
Patients and methods: 104 ambulatory and in-hospital patients (41 women, median age: 65 years, interquartiles: 48-72.5 years; 63 men, median age: 63 years, interquartiles: 51.3-72.5 years) undergoing long-term hemodialysis were investigated. Patients were followed up for 6 months for all kinds of fatal events and nonfatal cardiac events. Serum levels of cardiac TnT, two TnI assays (ACS:180 and Stratus II), CK (creatine kinase), and CK-MB were measured pre- and post-dialysis.
Results: Pre- and post-dialysis results were not different for TnT and TnI, while CK and CK-MB levels were significantly lower post-dialysis. Elevated (pre-)dialysis levels were found in 65.7% of patients for TnT (> 0.1 microg/l), in 32.4% for TnI (ACS:180, > 0.15 microg/l), in 2.9% for TnI (Stratus II, > 0.4 microg/l), in 5.7% for CK (> 170 U/l), and in 2.8% for CK-MB (> 1.0 microg/l). 6-month events were observed in 42 patients (40.4%; 20 fatal, 22 nonfatal). The relative risk for 6-month events was calculated to be 16.0-fold for TnT and 8.5-fold for a known coronary heart disease, while both TnI and CK-MB did not predict 6-month events independently.
Conclusions: TnT and a known coronary heart disease are relevant, independent risk factors in patients with chronic renal failure undergoing long-term hemodialysis.