Lower post-rewarming control temperature at 72 hours following targeted temperature management is associated with 1-year mortality after out-of-hospital cardiac arrest

Objective: This study investigated the relationship between post-rewarming control temperature and neurological outcomes using data from a multicenter post-cardiac arrest syndrome (PCAS) registry in Korea. Methods: We retrospectively analyzed data from the PCAS registry, which prospectively enrolled out-of-hospital cardiac arrest patients with sustained return of spontaneous circulation in the emergency departments of three urban hospitals between December 2013 and April 2021. Patients who received targeted temperature management (TTM) were included. Body temperature was measured at 4-hour intervals during the first 72 hours after the initiation of TTM. The post-rewarming control temperature was defined as the body temperature measured at 72 hours after TTM initiation. The primary outcome was a favorable neurological outcome, defined as a Cerebral Performance Category score of 1-2 at 1 year, and the secondary outcome was 1-year mortality. Results: Of the 1,591 patients in the registry, 289 were included in the analysis. A favorable neurological outcome occurred in 75 patients (25.9%). Patients with favorable neurological outcomes exhibited higher body temperatures at 4 hours and during the 48-72-hour period of TTM than those with unfavorable outcomes. Body temperature at 72 hours of TTM was independently associated with 1-year mortality (adjusted odds ratio [aOR], 0.56; 95% confidence interval [CI], 0.37-0.82; P=0.004), but not with favorable neurological outcomes at 1 year (aOR, 1.24; 95% CI, 0.75-2.09; P=0.399). Conclusion: A lower body temperature at 72 hours after TTM was independently associated with 1-year mortality.