Prehospital predictors of neurological outcomes in out-of-hospital cardiac arrest patients aged 95 years and older: A nationwide population-based observational study.

BACKGROUND: Population aging has rapidly progressed in Japan. However, few data exist regarding the characteristics of extremely elderly patients with out-of-hospital cardiac arrest (OHCA). We aimed to determine the prehospital predictors of one-month survival with favorable neurological outcomes (Cerebral Performance Category scale, category 1 or 2; CPC 1-2) in this population.

METHODS: We investigated 23,520 OHCA patients aged ≥95 years from a prospectively recorded, nationwide, Utstein-style Japanese database between 2008 and 2012. The primary study endpoint was one-month CPC 1-2 after OHCA.

RESULTS: The one-month CPC 1-2 rate was 0.27% (63/23,520). Only two variables were significantly associated with one-month CPC 1-2 in a multivariate logistic regression model: prehospital return of spontaneous circulation (ROSC) [adjusted odds ratio (aOR), 94.4; 95% confidential interval (CI), 50.1-191.7] and emergency medical service (EMS)-witnessed arrest (aOR, 5.1; 95% CI, 2.6-10.2). When stratified by these two predictors, the one-month CPC 1-2 rates were 20.2% (18/89) for patients who had both prehospital ROSC and EMS-witnessed arrest, 4.2% (33/783) for those who had prehospital ROSC without EMS-witnessed arrest, 0.28% (3/1065) for those who had EMS-witnessed arrest without prehospital ROSC, and 0.04% (9/21,583) for those who had neither predictor, respectively.

CONCLUSIONS: The crucial prehospital predictors for one-month CPC 1-2 in elderly OHCA patients aged ≥95 years in Japan were prehospital ROSC and EMS-witnessed arrest and the former was the predominant predictor.