Biomarker Predicts Outcome in Persistently Unconscious Patients

A total of 700 patients were enrolled from sites partaking in the biomarker sub-study. Serum blood samples were drawn at 24 hours, 48 hours and 72 hours after return of spontaneous circulation (ROSC).

NSE analyses were performed at the clinical biology laboratory of the Centre Hospitalier de Luxembourg six months after follow-up was completed. The Roche hemolysis index was used to test all serum samples for hemolysis. Samples with a positive hemolysis index of greater than or equal to 500 mg/mL of hemoglobin were discarded. The NSE value in each sample was analyzed using the cobas e601 line with an Electro-chemi-luminescent-immuno-assay (ECLIA) kit yielding a measuring range of 0.05 ng/mL to 370 ng/mL.

A total of 685 (73%) patients participated in the study. At day three after OHCA 63 (9%) patients had died and 473 (69%) patients were not awake. In these patients, a single NSE measurement at 48 hours predicted poor outcome with an area under the receiver operating characteristics curve (AUC) of 0.83. A combination of all three NSE measurements yielded the highest discovered AUC of 0.88. Easily applicable combinations of serial NSE measurements did not significantly improve prediction over a single measurement at 48 hours (AUC 0.58–0.84 versus 0.83).

The authors concluded that NSE is a strong predictor of poor outcome after OHCA in persistently unconscious patients undergoing TTM, and NSE is a promising surrogate marker of outcome in clinical trials. While combinations of serial NSE measurements may provide an increase in overall prognostic information, it is unclear whether actual clinical prognostication with low false-positive rates is improved by application of serial measurements in persistently unconscious patients. The study was published on January 18, 2017, in the journal Public Library of Science ONE.