Effectiveness of lower target temperature therapeutic hypothermia in post-cardiac arrest syndrome patients with a resuscitation interval of ≤30 min.

Background: Therapeutic hypothermia (TH) is a standard strategy to reduce brain damage in post-cardiac arrest syndrome (PCAS) patients. However, it is unknown whether the target temperature should be adjusted for PCAS patients in different states.

Methods: Participants in the J-PULSE-Hypo study database were divided into lower (32.0-33.5 °C; Group L) or moderate (34.0-35.0 °C; Group M) temperature groups. Primary outcome was a favourable neurological outcome (proportion of patients with a Glasgow-Pittsburgh Cerebral Performance Category [CPC] of 1-2 on day 30). We compared between the two groups and in subgroups of patients divided by age and resuscitation interval (interval from collapse to return of spontaneous circulation) by propensity score (PS) analysis.

Results: Overall, 467 participants were analysed. The proportions of patients with favourable neurological outcomes were as follows (Group L vs. Group M) (OR; Odds ratio): all patients, 64 % (n = 42) vs. 55 % ((n = 424) (PS; OR 1.381 (0.596-3.197)), P = 0.452) and resuscitation interval ≤ 30 min, 88 % (n = 24) vs. 64 % ((n = 281) (PS; OR 7.438 (1.769-31.272)), P = 0.007).

Conclusions: PCAS patients with a resuscitation interval of <30 min may be candidates for TH with a target temperature of <34 °C.

Trial Registration: University Hospital Medical Information Network (UMIN) Clinical Trials Registry UMIN000001935; available at: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000002348&language=J.