Troponin I in Acute Decompensated Heart Failure: Insights from the ASCEND-HF Study

AIMS: 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. METHODS AND RESULTS: 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. CONCLUSION: 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.