384 Association of Sex With Individual Factors of Out-of-Hospital Cardiac Arrest and Outcomes

Abstract

The 2014 Academic Emergency Medicine Consensus Conference Cardiovascular Resuscitation Working Group specifically noted exploring sex-specifics in out-of-hospital cardiac arrest (OHCA) as a research priority to enhance targeted resuscitation and improve outcomes. Previous studies have highlighted sex disparity in survival from OHCA. It is unclear whether this is due to differences in cardiac arrest characteristics, sex differences in treatment, or both. Specifically, there is conflicting evidence regarding sex and neurological outcome. We sought to evaluate the association of sex and OHCA survival outcomes within one regional cardiac system of care. This was a retrospective analysis of OHCA included in the Cardiac Arrest Registry to Enhance Survival (CARES). Data was queried between September 2013 and December 2016. We excluded events occurring in nursing homes, health care facilities, and airports. Sex was tested for association with rates of shockable rhythms, bystander cardiopulmonary resuscitation (BCPR), return of spontaneous circulation (ROSC), hospital survival, and cerebral performance category (CPC) of 1 or 2. Out of 7,765 OHCA in the registry during the study period, 5957 cases (41% female) cases met the inclusion criteria. Females had frequency of 42% of witnessed arrest versus 58% in males. For bystander CPR, females had a rate of 15.1% versus males had a rate of 17.4%. In adjusted models accounting for cardiac arrest characteristics, race, location, and age, females were less likely to present with a shockable rhythm (OR 0.73, 95% CI 0.6305, 0.8494), but had higher chances of ROSC (OR 1.44, 95% CI 1.2647, 1.5998), hospital admission (OR 1.45, 95% CI 1.2729, 1.6546) and survival to hospital discharge compared to males (OR 1.25, 95% CI 1.0217, 1.5259 ). However, females and males had similar likelihood of favorable CPC (OR 1.08, 95% CI 0.8311, 1.3924). After adjusting for shockable rhythms, sex did not have a statistically significant association with CPC (OR 1.22, 95% CI 0.9314, 1.6106). Our analysis thus far indicates that there is minimal sex differences in rates of BCPR in our specific community over the 3 years of data collected. However, females do have a lower likelihood of having a shockable rhythm as the first recorded rhythm by emergency medical services compared to males. Despite more unfavorable out-of-hospital cardiac arrest characteristics in females, hospital survival with favorable neurologic outcome was similar among both sexes in our regional cardiac system of care. Further analysis of sex-related differences at the hospital level needs to be explored to understand the sex disparity in OHCA.