The Extent of Myocardial Injury During Prolonged Targeted Temperature Management After Out-of-Hospital Cardiac Arrest.

Grejs, Anders Morten; Gjedsted, Jakob; Thygesen, Kristian; Lassen, Jens Flensted; Rasmussen, Bodil Steen; Jeppesen, Anni Nørgaard; Duez, Christophe Henri Valdemar; Søreide, Eldar; Kirkegaard, Hans

AIM 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-cTnTAUC of 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-MBAUC of 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. CONCLUSION This study of comatose out-of-hospital cardiac arrest survivors showed no difference between the extents of myocardial injury estimated by hs-cTnTAUC of prolonged targeted temperature management of 48 hours vs 24 hours, although the CK-MBAUC was 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.