When people suffer cardiac arrests out-of-hospital, their brains may
be oxygen-deprived for some time, causing neurological injuries and
loss of consciousness. Neurological injury from lack of oxygen is the
primary cause of death following cardiac arrest, so accurate prognostic
information about brain recovery is key to making decisions about
The biomarker neuron-specific enolase is a strong predictor of brain
recovery in heart attack patients who are unconscious for three or more
days, according to a study published in the journal PLOS ONE
by Sebastian Wiberg from Copenhagen University Hospital in Denmark and colleagues.
‘The biomarker neuron-specific enolase (NSE) is a strong predictor of brain recovery in heart attack patients who are unconscious for three or more days.’
The authors of the present study retrospectively examined a subset
of data collected during the Targeted Temperature Management (TTM)
clinical trial, which examined the benefits of lowering body
temperatures in patients who had suffered heart attacks out-of-hospital.
Wiberg and colleagues analyzed data from the TTM trial on 685 adults
who had been admitted to hospital in a comatose state after suffering a
cardiac arrest. These patients' blood was drawn one, two and three days
after the heart attack to measure levels of the protein biomarker
neuron-specific enolase (NSE), which is released into the blood by
After conducting statistical analyses of this subset of data, the
researchers found that for patients who remained comatose for three days
or longer, a combination of all three NSE measurements was a strong
predictor of recovery outcomes. The NSE measurement taken two days after
cardiac arrest was particularly useful. However, NSE was not a useful
outcome predictor for patients who awakened from comas within three days.
Current guidelines for management of comatose cardiac arrest
patients call for serial measurements of NSE, advice which is supported
by this study. However, the authors note that a prospective cohort study
should be done to verify these results.