Abstract 13943: Time to Target Temperature and Outcome After Out-of-Hospital Cardiac Arrest

Abstract

Background: We studied in the association between time to target temperature (TTT) and outcome in patients enrolled in the Target Temperature Management (TTM-Trial) after out of hospital cardiac arrest (OHCA). Methods: The TTM-Trial is a randomized study that investigated temperature management at 33 or 36°C for 24 hours (h) in 950 patients. We defined TTT as the time from return of spontaneous circulation (ROSC) to a bladder temperature <34°C or <36.5°C. Results: Target temperature after ROSC was achieved in a median time of 5.3h and 2.9h, respectively in the 33°C and 36°C group. In patients randomized at 33°C a shorter TTT was associated with worse survival (Log-rank <0.0001) and TTT was a predictor of survival with a hazard ratio (HR) for mortality of 0.68 (95%CI 0.56-0.81). There was a linear relationship between TTT and log relative hazard of mortality (P= 0.29). After multivariate analysis TTT had a HR for mortality of 0.81 (95%CI 0.67-0.98). In addition, TTT was a predictor of poor neurological outcome with an odds ratio (OR) of 0.63 (95%CI 0.48-0.83) with a linear relationship between TTT and log odds of poor neurological outcome (P= 0.38). After adjustment for confounders, TTT was not any longer an independent predictor of poor neurological outcome (OR 0.87, 95%CI 0.64-1.18). In patients randomized at 36°C, TTT was not associated with survival and after adjustment for confounders TTT was no longer an independent predictor of survival (HR 0.81, 95%CI 0.46-1.43) and of poor neurological outcome (OR 1.05, 95%CI 0.54-2.03). Conclusions: A faster TTT in patients cooled at 33°C was associated with increased mortality and was a predictor of mortality and poor neurological outcome. TTT remained an independent predictor of mortality after multivariate analysis.