Abstract
Background: Elevated cardiac troponin I (cTnI) levels during COPD exacerbations predict long-term mortality (COPD 2009;6:155-61). The times at which these deaths occur is unknown. We used a time-to-event approach to further characterise the prognostic significance of this biomarker.
Methods: 237 COPD patients (127 male, 73±11yrs) admitted with exacerbations between July 2008-9, and with a measured cTnI within 24h of admission were retrospectively identified. Clinical information was retrieved from the electronic patient record.
Results: Admission cTnI was “undetectable” (U, <0.02μg/L) in 15%, “measurable” (M, 0.02-0.05μg/L) in 59% and “elevated” (E, >0.05μg/L) in 26% of patients. The table shows mortality at various timepoints.
Figure 1 illustrates survival post-admission by initial cTnI level.
On Cox regression, cTnI level predicted survival (p=0.003) independently of inflammatory markers, haemoglobin, creatinine or cancer.
Conclusions: Any detectable cTnI is independently associated with increased post-exacerbation mortality, with increasing risk at higher concentrations. Excess deaths in patients with detectable cTnI occur in the first 30 days post-admission. Elucidating underlying mechanisms of cTnI rise may identify new opportunities to improve outcomes following COPD exacerbations.
- © 2011 ERS