Association Between Direct Transport to a Cardiac Arrest Centre and Survival Following Out-of-Hospital Cardiac Arrest: A Propensity-Matched Aotearoa New Zealand Study

Abstract

Background and Objectives: Direct transport to a cardiac arrest centre following out-of-hospital cardiac arrest may be associated with higher survival. However, there is limited evidence available to support this within the New Zealand context. This study used a propensity score-matched cohort to investigate whether direct transport to a cardiac arrest centre improved survival in New Zealand.

Methods: A retrospective cohort study was conducted using the Aotearoa New Zealand Paramedic Care Collection (ANZPaCC) database for adults treated for out-of-hospital cardiac arrest of presumed cardiac aetiology between 1 July 2018 to 30 June 2023. Propensity score-matched analysis was used to investigate survival at 30-days post-event according to the receiving hospital being a cardiac arrest centre versus a non-cardiac arrest centre.

Results: There were 2,297 OHCA patients included. Propensity matching resulted in 554 matched pairs (n = 1108). Thirty-day survival in propensity score-matched patients transported directly to a cardiac arrest centre (56%) versus a non-cardiac arrest centre (45%) was not significantly different (adjusted Odds Ratio 0.78 95%CI 0.54, 1.13, p = 0.19). Shockable presenting rhythm, bystander CPR, and presence of STEMI were associated with a higher odds of 30 day survival (p < 0.05). Māori or Pacific Peoples ethnicity and older age were associated with lower survival (p < 0.05).

Conclusions: This study found no statistically significant difference in outcomes for OHCA patients transferred to a cardiac arrest compared to a non-cardiac arrest centre. However, the odds ratio of 0.78, equivalent to a 22% decrease in 30-day mortality, is consistent with benefit associated with management by a cardiac arrest centre. Further research in larger cohorts with detailed information on known outcome predictors, or large randomised clinical trials are needed.