Sex-specific differences and outcome in elderly patients after survived out-of-hospital cardiac arrest

Background Little is known about sex differences in elderly patients after out-of-hospital cardiac arrest (OHCA) with return of spontaneous circulation (ROSC) and subsequent target temperature management (TTM). Therefore, this study was designed to evaluate sex-specific differences in survival and neurological outcome in elderly patients at 28-day and 180-day follow-up. Methods A total of 468 nontraumatic OHCA survivors with preclinical ROSC and an age of >= 65 years were included in this study. Sex-specific differences in survival and a favorable neurological outcome according to the cerebral performance category (CPC) score were evaluated as clinical endpoints. Results Of all participants included, 70.7% were men and 29.3% women. Women were significantly older (p = 0.011) and were more likely to have a nonshockable rhythm (p = 0.001) than men. Evaluation of survival rate and favorable neurological outcome by sex category showed no significant differences at 28-day and 180-day follow-up. In multiple stepwise logistic regression analysis, age (odds ratio 0.932 [95% confidence interval 0.891-0.951], p = 0.002) and time of hypoxia (0.899 [0.850-0.951], p < 0.001) proved to be independent predictors of survival only in male patients, whereas an initial shockable rhythm (4.325 [1.309-14.291], p = 0.016) was associated with 180-day survival in female patients. The majority of patients (93.7%) remained in the same CPC category when comparing 28-day and 180-day follow-up. Conclusion Our results show no significant sex-specific differences in survival or favorable neurological outcome in elderly patients after having survived OHCA, but sex-specific predictors for 180-day survival. Moreover, the neurological assessment 28 days after the index event also seems to provide a valid indication for the further prognosis in elderly patients.