Out-of-hospital cardiac arrests in the older population in Ireland

Introduction: Age influences survival from an out-of-hospital cardiac arrest (OHCA) but it is unclear to what extent. Improved understanding of the impact of increasing age may be helpful in improving decision making on who should receive attempted resuscitation to optimise outcomes and minimise inappropriate end-of-life management. Our aim is to describe the demographics, characteristics and outcomes following resuscitation attempts in OHCA patients aged 70 years and older in Ireland.Methods: Data were extracted from the national OHCA Register. Patient and event characteristics were compared across three age categories (70-79; 80-89; ≥90 years). Multivariable logistic regression was used to determine the predictors of the primary outcome (survival to hospital discharge).Results: A total of 2281 patients aged 70 years and older were attended by emergency medical services and had resuscitation attempted between 2012 and 2014. Overall survival to hospital discharge was 2.9%. For those aged 70-79 years, 80-89 years, 90 years and older survival to hospital discharge in each age group was 4.0%, 1.8% and 1.4%, respectively. Older age (adjusted OR (AOR) 0.95 95% CI 0.90 to 0.99) and having an arrest in the subjects own home (AOR 0.14 95% CI 0.07 to 0.28) were independent predictor associated with reduced odds of survival to hospital discharge. An initial shockable rhythm (AOR 17.9. 95% CI 8.19 to 39.2) and having a bystander witnessed OHCA (AOR 3.98. 95% CI 1.38 to 11.50) were independent predictors associated with increased odds of survival to hospital discharge.Conclusion: In those aged 70 years and older, the rate of survival to hospital discharge declined with increasing age group. Younger age, an initial shockable rhythm and witnessed arrest were independent predictors of survival to hospital discharge.