Abstract 139: Targeted Blood Pressure, Oxygenation, and Duration of Device-Based Fever Prevention After Out-of-Hospital Cardiac Arrest - Effects on 1 Year Survival

Abstract

Background: In the post-resuscitation phase after cardiac arrest various treatment modalities have been proposed for improving outcomes. The “Blood Pressure and Oxygenation Targets in Post Resuscitation Care” (BOX) trial investigated whether, a higher versus lower blood pressure target, a liberal versus restrictive oxygenation target, and a longer versus shorter duration of device-based fever prevention in comatose patients could improve outcomes. No differences in rates of discharge from hospital with severe disability or dying from all causes at 90 days were found for neither of the 3 interventions However, the long-term effects of these interventions are unknown. Objective: To investigate the effects of each of the 3 interventions of the BOX-trial on 1-year mortality rates. Methods: In the BOX trial (NCT03141099), comatose resuscitated out-of-hospital cardiac arrest patients were randomly assigned to the following interventions at hospital admission: 1. A blood pressure target of either 63 mmHg or 77 mmHg (blinded); 2. An arterial oxygenation target of 68 to 75 mmHg or 98 to 105 mmHg; 3. Device-based fever prevention administered as an initial 24 hours at 36°C and then either 12 or 48 hours at 37°C a total of 36 or 72 hours. Patients were followed for 1 year for the occurrence of death from all causes, and mortality rates are reported separately for each of the 3 interventions. Results: For all three interventions 789 patients were included in the analyses. For the interventions of higher compared to lower blood pressure targets, the 1-year mortality rates were 36% (143 of 393) and 35% (138 of 396), respectively (log-rank p=0.47). For the interventions of liberal compared to restrictive oxygenation targets the 1-year mortality rates were 37% (146 of 395) and 34% (135 of 394), respectively (p=0.46). For the interventions of device-based fever prevention for a total of 72 hours compared to 36 hours the 1-year mortality rates were 36% (142 of 396) and 35% (139 of 393) respectively (p=0.89). Conclusions: There were no indications of differentiated rates of mortality at 1 year for neither a higher compared to lower targeted blood pressure, a liberal compared to restrictive oxygenation target, nor a longer compared to shorter duration of device-based fever prevention.