Survival and Neurologic Outcomes of Out-of-Hospital Cardiac Arrest Patients Who Were Transferred after Return of Spontaneous Circulation for Integrated Post-Cardiac Arrest Syndrome Care: The Another Feasibility of the Cardiac Arrest Center

It has been proven that safety and efficiency of out-of-hospital cardiac arrest (OHCA) patients is transported to specialized hospitals that have the capability of performing therapeutic hypothermia (TH). However, the outcome of the patients who have been transferred after return of spontaneous circulation (ROSC) has not been well evaluated. We conducted a retrospective observational study between January 2010 to March 2012. There were primary outcomes as good neurofunctional status at 1 month and the secondary outcomes as the survivals at 1 month between Samsung Medical Center (SMC) group and transferred group. A total of 91 patients were enrolled this study. There was no statistical difference between good neurologic outcomes between both groups (38% transferred group vs. 40.6% SMC group, P=0.908). There was no statistical difference in 1 month survival between the 2 groups (66% transferred group vs. 75.6% SMC group, P=0.318). In the univariate and multivariate models, the ROSC to induction time and the induction time had no association with good neurologic outcomes. The good neurologic outcome and survival at 1 month had no significant differences between the 2 groups. This finding suggests the possibility of integrated post-cardiac arrest care for OHCA patients who are transferred from other hospitals after ROSC in the cardiac arrest center. Graphical Abstract Keywords: Hypothermia Therapy, Heart Arrest, Cardiopulmonary Resuscitation INTRODUCTION Out-of-hospital cardiac arrest (OHCA) remains as a common public health problem and a leading cause of morbidity and mortality (1). Systematic, post-cardiac arrest care after return of spontaneous circulation (ROSC) can improve the survival and neurologic outcome of OHCA patients (2, 3). In particular, recent studies have demonstrated that therapeutic hypothermia (TH) is an important resuscitation therapy that improves the rate of survival and relieves unfavorable neurological outcomes in cardiac arrest survivors (2, 4). Despite TH being emphasized, the medical community has been slow to adopt TH in the hospital environment (5, 6). This may be due to some barriers, such as a lack of knowledge about TH, financial barriers, and logistic barriers (6, 7). Thus, it is difficult to perform systematic post-cardiac arrest care including TH in all hospitals. Furthermore, the differences in post cardiac arrest mortality between hospitals have been reported (3, 8). In a well-established hospital setting, post resuscitation care including therapeutic hypothermia can improve outcomes among post-cardiac arrest patients (3, 8, 9). Therefore, it has been suggested that the resuscitation center could provide regional post cardiac-arrest care (9, 10, 11, 12, 13). Recently, some studies have proven that the transported distance and time did not affect the outcomes of OHCA patients (10, 11, 12). However, these studies have focused on the transport of OHCA patients from the field to the hospital. There was a study to evaluate the outcomes of OHCA patients who have been transported to a well-organized regional center after ROSC (14). This study showed that the outcome of inter-hospital transported patients with pre-transferred cooling did not differ from patients who had directly visited the regional center. However, a delay in the initiation of cooling was associated with an increased risk of death. Despite pre-transferred TH has potential benefit (14), induction of prehospital TH after ROSC in OHCA is not widely used due to a lack of effective equipment, manpower, and specific guidelines (15). Therefore, most resuscitated patients start TH after their arrival at the hospital (15). For this reason, we hypothesized that the patients transferred after ROSC would have delayed initiation of cooling, which would produce poor outcome in the transferred patients compared to directly visited patients. The aim of this study was to evaluate the outcome differences between transferred group and the Samsung Medical Center (SMC) group.