• Jakob Hartvig Thomsen, Niklas Nielsen, Christian Hassager, Michael Wanscher, Steen Pehrson, Lars Køber, John Bro-Jeppesen, Helle Søholm, Matilde Winther-Jensen, Tommaso Pellis, Michael Kuiper, David Erlinge, Hans Friberg, and Jesper Kjaergaard.
• 1Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark. 2Department of Anesthesia and Intensive Care, Helsingborg Hospital, Helsingborg, Sweden. 3Department of Thoracic Anaesthesiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark. 4Department of Anaesthesia and Intensive Care, Santa Maria degli Angeli, Pordenone, Italy. 5Department of Intensive Care, Leeuwarden Medical Centrum, Leeuwarden, The Netherlands. 6Department of Cardiology, Lund University Hospital, Lund, Sweden. 7Department of Anesthesia and Intensive Care, Skåne University Hospital, Lund University, Lund, Sweden.
• Crit. Care Med. 2016 Feb 1; 44 (2): 308-18.

ObjectivesBradycardia is common during targeted temperature management, likely being a physiologic response to lower body temperature, and has recently been associated with favorable outcome following out-of-hospital cardiac arrest in smaller observational studies. The present study sought to confirm this finding in a large multicenter cohort of patients treated with targeted temperature management at 33°C and explore the response to targeted temperature management targeting 36°C.DesignPost hoc analysis of a prospective randomized study.SettingThirty-six ICUs in 10 countries.PatientsWe studied 447 (targeted temperature management = 33°C) and 430 (targeted temperature management = 36°C) comatose out-of-hospital cardiac arrest patients with available heart rate data, randomly assigned in the targeted temperature management trial from 2010 to 2013.InterventionsTargeted temperature management at 33°C and 36°C.Measurements And Main ResultsEndpoints were 180-day mortality and unfavorable neurologic function (cerebral performance category 3-5). Patients were stratified by target temperature and minimum heart rate during targeted temperature management (< 50, 50-59, and ≥ 60 beats/min [reference]) at 12, 20, and 28 hours after randomization. Heart rates less than 50 beats/min and 50-59 beats/min were recorded in 132 (30%) and 131 (29%) of the 33°C group, respectively. Crude 180-day mortality increased with increasing minimum heart rate (< 50 beats/min = 32%, 50-59 beats/min = 43%, and ≥ 60 beats/min = 60%; p(log-rank) < 0.0001). Bradycardia less than 50 beats/min was independently associated with lower 180-day mortality (hazard ratio(adjusted) = 0.50 [0.34-0.74; p < 0.001]) and lower odds of unfavorable neurologic outcome (odds ratio(adjusted) = 0.38 [ 0.21-0.68; p < 0.01]) in models adjusting for potential confounders including age, initial rhythm, time to return of spontaneous circulation, and lactate at admission. Similar, albeit less strong, independent associations of lower heart rates and favorable outcome were found in patients treated with targeted temperature management at 36°C.ConclusionsThis study confirms an independent association of bradycardia and lower mortality and favorable neurologic outcome in a large cohort of comatose out-of-hospital cardiac arrest patients treated by targeted temperature management at 33°C. Bradycardia during targeted temperature management at 33°C may thus be a novel, early marker of favorable outcome.

25 keywords...

hide…