Abstract 346: Targeted Temperature Management is Associated with Improved Neurological Outcomes in Witnessed Out-of-hospital Cardiac Arrest Patients Who Achieve Early Return of Spontaneous Circulation

Abstract

Background: Previous randomized controlled trials demonstrated the efficacy of targeted temperature management (TTM) in out-of-hospital cardiac arrest (OHCA) patients with both shockable and non-shockable rhythm. Real-world evidence for TTM using large OHCA database are scarce, and no study has investigated the relationship between TTM and time-to-return of spontaneous circulation (ROSC). Methods: The Japanese Association for Acute Medicine - out-of-hospital cardiac arrest (JAAM-OHCA) Registry is a multicenter, prospective, observational registry including 34,754 OHCA patients between 2014 and 2017. Patients with witnessed non-traumatic OHCA who had been resuscitated and were in a coma were included. Eligible patients were divided into two groups according to the use of TTM. The primary outcome was defined as a Cerebral Performance Categories (CPC) Scale 1-2 at 30 days after OHCA. The propensity score matching analysis was used. The cubic spline analysis of the odds ratio of CPC 1-2 for TTM use by time-to-ROSC was performed. Results: Out of 34,754 patients with OHCA, 5,261 patients were included. The mean age was 70.3 years, and 3,417 (65.0%) were male. CPC 1-2 was more frequently observed in the TTM group in propensity score matching analysis (15.1% vs. 8.5%; odds ratio 1.92; 95% confidence interval 1.04-3.53; P=0.037). The cubic spline analysis showed that TTM was associated with CPC 1-2 in witnessed OHCA patients, which did not reach statistical significance in patients with time-to-ROSC longer than 50 min. Conclusions: TTM was associated with better neurological outcomes in witnessed OHCA patients, especially when patients were resuscitated within 50 min after collapse.