Cardiac Troponin Release is Associated with Biomarkers of Inflammation and Ventricular Dilatation During Critical Illness

INTRODUCTION: Troponin release is common during critical illness. We hypothesized that there was an association between cardiac troponin T (cTnT) and biomarkers of systemic inflammation and ventricular dilatation.

METHODS: In an observational prospective cohort study, we enrolled consecutive adult patients admitted for non-cardiac reasons to the Intensive Care Unit (ICU) in 2 tertiary care centers. We measured cTnT, C-reactive protein (CRP), Interleukin-6 (IL-6), procalcitonin (PCT) and N-terminal pro brain natriuretic peptide (NT-proBNP) daily in the first week, and on alternate days in the second week. Using a peak cTnT cut-off ≥15ng/L and concomitant changes on electrocardiogram (ECG), patients were categorised as "definite myocardial infarction (MI)", "possible MI", "cTnT rise only" or "no cTnT rise". Within each group, associations between CRP, IL-6, PCT, NT-proBNP and cTnT were investigated using mixed effect models.

RESULTS: 172 patients were included in the analysis of whom 84% had a cTnT rise ≥15ng/L. 21 patients (12%) had a definite MI, 51 (30%) had a possible MI and 73 (42%) had a cTnT rise only. At time of peak cTnT, 71% of patients were septic and 67% were on vasopressors.Multivariable analysis showed a significant association between cTnT and IL-6 in all patients with a cTnT rise independent of age, gender, renal function and cardiovascular risk factors. In patients without a definite MI, cTnT levels were significantly associated with PCT and NT-proBNP values. In patients without elevated cTnT levels, there was no associated NT-proBNP rise.

CONCLUSIONS: In ICU patients admitted for non-cardiac reasons, serial cTnT levels were independently associated with markers of systemic inflammation and NT-proBNP.