Cardiac troponins I and T in hemodialysis patients without acute coronary syndrome.

BACKGROUND: There is a reluctance to use cardiac troponins (cTn) for the monitoring of acute coronary syndrome (ACS) in hemodialysis (HD) patients because renal failure per se is thought to lead to increased cTn levels. The aim of this study was to analyse the proportion of patients with increased cTn levels in HD patients without ACS.
METHODS: cTnI was measured with the AccuTnI(trade mark) from Beckman (cTnI-B) and Troponin I Stat(trade mark) from Dade Behring (cTnI-DB) assays; cTnT was measured with the third generation assay from Roche. The study included 105 HD patients. The clinical outcomes were determined after 2.5 years.
RESULTS: Considering the receiver operator characteristic (ROC) cutoff, the proportion of patients with elevated cTnI-B, cTnI-DB and cTnT levels was respectively 2%, 3% and 27%. The proportion of patients with abnormal cTn values increased when a lower cutoff value was considered, based on the 99th percentile of a reference population with a coefficient of variation of less than 10% (99th percentile-10% CV cutoff). The proportion of patients with elevated values did not differ before and after the HD session. The 2.5 years mortality was associated with increased levels of cTnT but not with increased levels of cTnI.
CONCLUSIONS: When the ROC cutoff is applied, cTnI assays are suitable for the monitoring of ACS in HD patients. cTnT could lead to false positive diagnosis of myocardial infarction, however it is predictive of long-term mortality. The 99th percentile-10% CV cutoff does not seem appropriate in HD patients.