Background Survival following out-of-hospital cardiac arrest (OHCA) depends on the Chain of Survival, which spans from bystander cardio-pulmonary resuscitation to in-hospital treatment. There is an increased interest in regionalisation of post-OHCA care, which includes ambulances bypassing the nearest hospital in favour of OHCA centres. This study examined the association between admission to OHCA centres and survival to hospital discharge for adults following OHCA of presumed cardiac aetiology.

Methods We undertook a multicentre retrospective observational study of patients transferred to hospital after OHCA of presumed cardiac aetiology in three ambulance services in England. We used propensity score matching to compare rates of survival to hospital discharge in patients admitted to OHCA centres (defined as either 24/7 PPCI availability or >100 OHCA admissions per year) to rates of survival of patients admitted to non-centres.

Results Between January 2017 and December 2018, 10,650 patients with OHCA were included in the analysis. After propensity score matching, admission to a hospital with 24/7 PPCI availability or a high-volume centre was associated with an absolute improvement in survival to hospital discharge of 2.5% and 2.8%, respectively. The corresponding odds ratios and 95% confidence intervals were 1.69 (1.28 to 2.23) and 1.41 (1.14 to 1.75), respectively. The results were similar when missing values were imputed. In subgroup analyses, the association between admission to an OHCA centre and improved rates of survival was mainly seen in patients with OHCA due to shockable rhythms, with no or minimal potential benefit for patients with asystole as first presenting rhythm.

Conclusions Following OHCA, admission to an OHCA centre is associated with a moderate improvement in survival to hospital discharge. A corresponding bypass policy would need to consider the resulting increased workload for OHCA centres and longer ambulance transfer times.