Troponin I in acute decompensated heart failure: insights from the ASCEND-HF study

We examined the prognostic importance of cardiac troponin I (cTnI) in a cohort of patients enrolled in the ASCEND-HF study of nesiritide in acute decompensated heart failure (ADHF). Circulating troponins are a prognostic marker in patients with ADHF. Contemporary assays with greater sensitivity require reassessment of the significance of troponin elevation in HF. Cardiac troponin I was measured in a core laboratory in 808 ADHF patients enrolled in the ASCEND-HF biomarkers substudy using a sensitive assay (VITROS Trop I ES, Ortho Clinical Diagnostics) with a lower limit of detection of 0.012 ng/mL and a 99th percentile upper reference limit (URL) of 0.034 ng/mL. Patients with clinical evidence of acute coronary syndrome or troponin 5 the URL were excluded. Multivariable modelling was used to assess the relationship between log(cTnI) and in-hospital and post-discharge outcomes. Baseline cTnI was undetectable in 22 and elevated above the 99th percentile URL in 50 of subjects. cTnI levels did not differ based on HF aetiology. After multivariable adjustment, higher cTnI was associated with worsened in-hospital outcomes such as length of stay (P 0.01) and worsening HF during the index hospitalization (P 0.01), but was not associated with worsened post-discharge outcomes at 30 or 180 days. The relationship between cTnI and outcomes was generally linear and there was no evidence of a threshold effect at any particular level of cTnI. cTnI is elevated above the 99th percentile URL in 50 of ADHF patients and predicts in-hospital outcome, but is not an independent predictor of long-term outcomes.