title: The Extent of Myocardial Injury During Prolonged Targeted Temperature Management After Out-of-Hospital Cardiac Arrest.
abstract: OBJECTIVE
  The aim of this study is to evaluate the extent of myocardial injury by cardiac biomarkers during prolonged targeted temperature management of 24 hours vs 48 hours after out-of-hospital cardiac arrest.
  
  
  METHODS
  This randomized Scandinavian multicenter study compares the extent of myocardial injury quantified by area under the curve (AUC) of cardiac biomarkers during prolonged targeted temperature management at 33°C ± 1°C of 24 hours and 48 hours, respectively. Through a period of 2.5 years, 161 comatose out-of-hospital cardiac arrest patients were randomized to targeted temperature management for 24 hours (n = 77) or 48 hours (n = 84). The AUC was calculated using both high-sensitivity cardiac troponin T (hs-cTnTAUC) and creatine kinase-myocardial band (CK-MBAUC) that were based upon measurements of these biomarkers every 6 hours upon admission until 96 hours after reaching target temperature.
  
  
  RESULTS
  The median hs-cTnTAUCof 33,827 ng/L/h (interquartile range [IQR] 11,366-117,690) of targeted temperature management at 24 hours did not differ significantly from that of 28,973 ng/L/h (IQR 10,656-163,655) at 48 hours. In contrast, the median CK-MBAUCof 1829 μg/L/h (IQR 800-6799) during targeted temperature management at 24 hours was significantly lower than that of 2428 μg/L/h (IQR 1163-10,906) within targeted temperature management at 48 hours, P <.05.
  
  
  CONCLUSIONS
  This study of comatose out-of-hospital cardiac arrest survivors showed no difference between the extents of myocardial injury estimated by hs-cTnTAUCof prolonged targeted temperature management of 48 hours vs 24 hours, although the CK-MBAUCwas significantly higher during 48 hours vs 24 hours. Hence, it seems unlikely that the duration of targeted temperature management has a beneficial effect on the extent of myocardial injury after out-of-hospital cardiac arrest, and may even have a worsening effect.
authors.affiliation: Research Center for Emergency Medicine, Aarhus University Hospital, Denmark; Department of Anesthesiology and Intensive Care Medicine, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark. Electronic address: anders.grejs@dadlnet.dk.
authors.forename: Anders Morten
authors.initials: AM
authors.lastname: Grejs
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Gjedsted
authors.affiliation: Department of Cardiology, Aarhus University Hospital, Denmark.
authors.forename: Kristian
authors.initials: K
authors.lastname: Thygesen
authors.affiliation: Department of Cardiology, Rigshospitalet, University Hospital of Copenhagen, Denmark.
authors.forename: Jens Flensted
authors.initials: JF
authors.lastname: Lassen
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Aalborg University, Denmark; Department of Clinical Medicine, Aalborg University, Denmark.
authors.forename: Bodil Steen
authors.initials: BS
authors.lastname: Rasmussen
authors.affiliation: Research Center for Emergency Medicine, Aarhus University Hospital, Denmark; Department of Anesthesiology and Intensive Care Medicine, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Anni Nørgaard
authors.initials: AN
authors.lastname: Jeppesen
authors.affiliation: Research Center for Emergency Medicine, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Christophe Henri Valdemar
authors.initials: CH
authors.lastname: Duez
authors.affiliation: Department of Anesthesiology and Intensive Care, Stavanger University Hospital, Norway; Department of Clinical Medicine, University of Bergen, Norway.
authors.forename: Eldar
authors.initials: E
authors.lastname: Søreide
authors.affiliation: Research Center for Emergency Medicine, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Kirkegaard
mesh_terms: D000368:Aged; D052279:Creatine Kinase, MB Form / Q000097:blood; D003422:Critical Care; D005260:Female; D006335:Heart Injuries / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications / Q000628:therapy*; D013997:Time Factors; D020107:Troponin T / Q000097:blood
chemical_list: D020107:Troponin T; D052279:Creatine Kinase, MB Form
keywords: Body temperature regulation; CK-MB; Heart arrest; Induced mild hypothermia; Out-of-hospital cardiac arrest; Targeted temperature management; Troponin T