Abstract 20023: Impact of Targeted Temperature During Therapeutic Hypothermia: A Pooling Analysis of Published Literature
Introduction: Two small RCTs demonstrated benefit of therapeutic hypothermia (TH) after out-hospital cardiac arrest (OHCA). We explored the benefit of targeted temperature during TH and also performed an updated meta-analysis to determine the intervention effect in the community.
Methods: We identified studies by searching electronic databases (MEDLINE, EMBASE and Cochrane Library). We selected RCTs and cohort studies restricted to those reporting achieved temperature during TH after OHCA, and describing mortality and neurological outcomes at discharge. Studies were assessed for risk of bias. Data from all individual hypothermia arms were pooled by achieved temperature. Pooled outcomes were compared across achieved temperatures. Meanwhile, we meta-analyzed controlled studies comparing hypothermia against normothermia.
Results: The search identified 32,275 studies of which 24 studies (34 hypothermia arms) were used in the pooling analysis and 14 controlled studies were meta-analyzed. Pooling analysis reported an overall in-hospital mortality of 47.2% with a rate of good neurological outcome at discharge of 38%. There was no difference in hospital mortality (p=0.86) or neurological outcomes at discharge (p=0.32) across temperatures (Figure 1). Sub-group analysis by rhythm showed a non-significant trend towards benefit when the lower temperature were applied to non-shockable rhythms. Meta-analysis demonstrated a MTH mortality (OR 0.51, 95%CI:0.41-0.64, I2=4.1%) and neuro-protective benefit (OR 2.48, 95%CI:1.91-3.22, I2=0%).
Conclusions: No discernible clinical benefit was noted based on target temperature achieved. The signal toward potential benefit when applying lower temperature to non-shockable rhythms warrants exploration. Consistent with prior meta-analysis, TH provides mortality and neuro-protective benefit after OHCA even when including cohort studies thought to be more representative of performance in the community.
Author Disclosures: A.L. Schenone: None. A. Cohen: None. G. Patarroyo: None. M.H. Shishehbor: None. V. Menon: None. A. Duggal: None.
- © 2015 by American Heart Association, Inc.