18 May Neuron-Specific Biomarker May Help Predict Outcome After Out-of-Hospital Cardiac Arrest
MedicalResearch: What is the background for this study? What are the main findings?
Dr Stammet: Patients hospitalized after an out-of-hospital cardiac arrest (OHCA) survive in about fifty percent and nine out of ten survivors have a good functional level six months after the arrest. However, in the early days after the cardiac arrest it is difficult to distinguish those who will survive from those who have very severe brain damage, not compatible with life. Biomarkers, like neuron specific enolase (NSE) have shown a prognostic value for outcome prediction. As a consequence of the widespread use of induced hypothermia, to improve survival and neurological function, for patients resuscitated form cardiac arrest, concerns have arisen about the impact of body temperature on previously published cut-off values for poor outcome. NSE has thus been questioned as a useful clinical tool. Recently, the Target Temperature Management trial (TTM-trial) published in November 2013 in the NEJM has shown no benefit of a target body temperature of 33°C over 36°C in patients with out-of-hospital cardiac arrest admitted to the ICU. In the present sub-study, we have analyzed the value of NSE to predict outcome in a cohort of 686 patients of the TTM-trial. Importantly, serial measurements of NSE at 24, 48 and 72 hours allowed accurate outcome prediction, with better performance than clinical and peri-arrest data alone. NSE did not significantly differ between temperature groups meaning that clinicians can use NSE as an adjunct prognostic tool regardless of the chosen temperature management strategy.
MedicalResearch: What should clinicians and patients take away from your report?
Dr Stammet: High, serial and increasing NSE values over time are strongly predictive of poor outcome after out-of-hospital cardiac arrest. The degree of targeted temperature management does not affect significantly the levels of NSE; identical NSE cut-offs are applicable for both temperature levels. Furthermore, biomarkers, like NSE are independent of sedation, unlike EEG or clinical examination, which can be strongly influenced by the level of sedative medications. One word of caution though: NSE values determined in haemolyzed blood samples must be discarded as haemolysis interferes with NSE measurement. Finally, no single outcome predictor should be used alone to decide on withdrawal of life supporting therapies for an individual patient; there must always be a bundle of parameters taken into consideration.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr Stammet: As brain-derived biomarkers are generally not influenced by sedation, their potential as outcome predictor after out-of-hospital cardiac arrest is appealing. Novel families of biomarkers like micro-RNAs (miRNAs) are under investigation. Brain-enriched miRNAs are released in the bloodstream after OHCA and thus may accurately reflect brain damage. Since miRNAs are able to regulate gene expression, they could even host potential therapeutic opportunities in the future. Therefore, this study motivates further research on the use of brain-derived biomarkers to tailor healthcare to each individual with cardiac arrest.
MedicalResearch.com Interview with: Dr Pascal Stammet (2015). Neuron-Specific Biomarker May Help Predict Outcome After Out-of-Hospital Cardiac Arrest
Last Updated on May 19, 2015 by Marie Benz MD FAAD