Changes Over 7 Years in Temperature Control Treatment and Outcomes After Out-of-Hospital Cardiac Arrest: A Japanese, Multicenter Cohort Study.

Temperature control is the only neuroprotective intervention suggested in current international guidelines for patients with return of spontaneous circulation after cardiac arrest, but the prevalence of temperature control therapy, temperature settings, and outcomes have not been clearly reported. We aimed to investigate changes over 7 years in provision of temperature control treatment among out-of-hospital cardiac arrest (OHCA) patients in Kanto region, Japan. Data of all adult OHCA patients who survived for more than 24 hours in the prospective cohort studies, SOS-KANTO 2012 (conducted from 2012 to 2013) and SOS-KANTO 2017 (conducted from 2019 to 2021), in Japan were included. We compared the prevalence of temperature control and the proportion of mild (≥35°C) and moderate (from 32°C to 34.9°C) hypothermia between the two study groups. We also performed a Cox regression analysis to evaluate 30-day mortality adjusted by temperature control therapy (none, moderate hypothermia, or mild hypothermia), age, sex, past medical history, witnessed status, bystander cardiopulmonary resuscitation, initial rhythm, location of arrest, and dataset (SOS-KANTO 2012 or 2017). We analyzed data from 2936 patients (n = 1710, SOS-KANTO 2012; n = 1226, SOS-KANTO 2017). Use of temperature control was lower (45.3% vs. 41.4%, p = 0.04), moderate hypothermia was lower (p < 0.01), and mild hypothermia was higher (p < 0.01) in SOS-KANTO 2017 compared with SOS-KANTO 2012. The survival rate was significantly higher for patients with mild (p < 0.01) and moderate (p < 0.01) hypothermia compared with those who did not receive temperature control therapy. Overall, the incidence of moderate hypothermia decreased and that of mild hypothermia increased and the use of temperature control decreased between the two studies conducted 7 years apart in the Kanto area, Japan. Temperature control management might improve survival of patients with OHCA.