Changes in cardiac troponin T measurements are associated with adverse cardiac events in patients with chronic kidney disease.

The purpose of this study was to determine whether long-term and short-term changes in cardiac troponin T (cTnT) were associated with adverse cardiac events (ACEs) in patients with chronic kidney disease. Long-term changes were defined as changes in cTnT between ED visits, and short-term changes were defined as changes between 2 consecutive serial cTnT measurements within an ED visit. A retrospective chart review of patients with chronic kidney disease with suspected acute coronary syndromes presenting to the ED between December 1999 and November 2003 was conducted. The primary outcome variable was an ACE which was a composite endpoint consisting of a discharge diagnosis of acute myocardial infarction, unstable angina, revascularization, cardiac dysrhythmias, all-cause mortality, or congestive heart failure exacerbation. The primary predictor of ACE abstracted from the charts was the initial cTnT measured during each ED presentation. There were 90 patients with 397 visits enrolled in the study. Using a mixed-models analysis of variance, cTnT was higher in the ACE group than in the non-ACE group (difference in log cTnT = 0.054, 95% CI 0.006-0.101) after adjusting for age, race, sex, dialysis status, and smoking history. No other variables were found to be associated with cTnT. To evaluate the clinical significance of acute changes in cTnT, a secondary analysis was performed on 64 patients with an initial cTnT measurement above 0.10 ng/mL. For in-hospital and 30-day ACE, a short-term increase in cTnT of 0.11 ng/mL had a positive likelihood ratio of 13.3 and 11.9, respectively. Long-term and short-term increases in cTnT are associated with an ACE.