Sex difference on neurological outcomes and post-cardiac arrest care in out-of-hospital cardiac arrest patients treated with targeted temperature management

Abstract Background: Conflicting results regarding sex-based differences in the outcomes of out-of-hospital cardiac arrest (OHCA) patients have been reported. Furthermore, no study has examined whether differences in in-hospital interventions and courses are driven by sex. This study evaluated the effect of sex on the in-hospital course as well as the survival rates and long-term neurological outcomes of OHCA patients treated with targeted temperature management.Methods: We retrospectively analyzed the Korean Hypothermia Network Prospective Registry composed of data collected from 22 hospitals in Korea between October 2015 and December 2018. To evaluate the effect of sex on patient outcomes, we created various multivariate logistic regression models. Regarding the difference in in-hospital courses, we compared daily total and SOFA sub-scores between the sexes and analyzed whether the decision regarding early cardiac interventions and limitations in in-hospital care were associated with sex.Results: The rate of good neurological outcomes after 6 months was higher in men (OR = 1.66, 95% CI: 1.26 2.17). However, when the results were adjusted using resuscitation variables and in-hospital variables were added, there was no significant difference between the two sexes (OR =1.22, 95% CI: 0.85 – 1.74; OR = 1.13, 95 CI: 0.76 – 1.68, respectively). There was no association between sex and outcome in patients of reproductive age and no interaction between age and sex. Regarding the in-hospital course, the daily total SOFA score was similar in both sexes whereas cardiovascular scores were higher in women on 2 and 3 days (on day 2, p = 0.006; on day 3, p = 0.017). The adjusted effect of sex was not associated with the clinician’s decision to perform early cardiac interventions except that men had more extracorporeal membrane oxygenation (ECMO) (OR=2.51, 95% CI: 1.11-5.66). The decision to discontinue life-sustaining treatment was determined by poor prognostic factors, not by sex. Conclusions: The findings suggested that men had more favorable 6-month neurological outcomes. However, after adjusting for confounders, there was no difference between the sexes. The results regarding in-hospital course were similar in men and women.