Target temperature management and post-extracorporeal cardiopulmonary resuscitation outcome: A post hoc analysis of the SAVE-J II Study

Background The conflicting results of previous analyses about hypothermia management in patients with out-of-hospital cardiopulmonary arrest have hindered the establishment of a uniform standard temperature setting for temperature control. This study investigated and compared the clinical outcomes of hypothermic (target temperature: 32–34°C) and normothermic (35–36°C) management of out-of-hospital cardiac arrest (OHCA) patients, treated with extracorporeal cardiopulmonary resuscitation (ECPR). Methods This secondary analysis of the SAVE-J II study, a retrospective, multicenter, registry study involving 36 participating institutions in Japan, was undertaken, and ECPR patients with a suspected cardiac etiology were included in this cohort. The primary outcome was survival at hospital discharge. Favorable neurological outcomes (5-point Glasgow-Pittsburgh Cerebral Performance Categories 1–2) constituted the secondary outcome. Multivariable logistic analysis, which was adjusted for potential confounders, was performed for the primary and secondary outcomes. Results Of the 949 participants of this study, 57% underwent hypothermic management. A total favorable neurological outcome at hospital discharge was identified in 164 patients (17%), and the survival rate was 35%. In multivariable analysis, with the primary and secondary endpoints as each dependent variable, and gender, age, witness, bystander CPR, electrocardiogram, low flow time, and causative disease as categorical covariates, hypothermic management compared to normothermic management in OHCA patients treated with ECPR, was not significantly associated with a favorable neurological outcome (adjusted odds ratio (aOR): 1.22: 95% CI: 0.85–1.74), but was associated with survival (aOR: 1.74: 95% CI: 1.31–2.32). Conclusions Compared to normothermic management, hypothermic management of OHCA patients treated with ECPR was not significantly associated with a favorable neurological outcome, but was associated with survival at hospital discharge. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by the Japan Society for the Promotion of Science KAKENHI to JK(JP19K18365) and YK (JP19K09419). The funding organization did not play any role in the study; the views expressed in this paper do not reflect the views of the Ministry. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The SAVE-J II Study was approved by the institutional review board of Kagawa University (approval number: 2018-110). For all participating centers, the requirement for patient consent was waived because of the retrospective nature of the study. The study was approved by the Teikyo University School of Medicine Research Ethics Committee (approval number: 23-005). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that support the findings of this study are available from the corresponding author upon reasonable request. The data that support the findings of this study are available from the corresponding author upon reasonable request.