Elsevier

Resuscitation

Volume 160, March 2021, Pages 118-125
Resuscitation

Clinical paper
Association between admission to a cardiac arrest centre and survival to hospital discharge for adults following out-of-hospital cardiac arrest: A multi-centre observational study

https://doi.org/10.1016/j.resuscitation.2021.01.024Get rights and content

Abstract

Aim

This study examined the association between admission to a cardiac arrest centre and survival to hospital discharge for adults following out-of-hospital cardiac arrest (OHCA).

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 (1.28–2.23) and 1.41 (1.14–1.75), 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 OHCA and asystole as first presenting rhythm.

Conclusion

Following OHCA, admission to a cardiac arrest 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.

Introduction

Survival following out-of-hospital cardiac arrest (OHCA) depends on the optimal implementation of each link in the Chain of Survival, which spans community training, Emergency Medical Services (EMS) response and post-resuscitation care in hospital.1 For in-hospital care, recent international literature suggests that admission of OHCA patients to hospitals which provide post-resuscitation care for a large volume of OHCA patients might result in higher rates of survival.2, 3 It is thought that these “OHCA centres” achieve better outcomes for patients with OHCA through early access to primary percutaneous coronary intervention (PPCI),4 targeted temperature management,5 and the expertise and optimised pathways generally associated with caring for a high-volumes of specific patient populations.6

In England, a recent national framework to improve the care of people following OHCA suggests that most patients with return of spontaneous circulation after OHCA should be transferred to an OHCA centre.7 However, a large database study undertaken in England examined a number of factors thought to affect survival following OHCA.8 Despite suggesting that early PCI is associated with better outcomes following OHCA, the study failed to demonstrate a clear survival benefit for patients admitted to OHCA centres. Similarly, a recent systematic review concluded that ‘very low certainty of evidence suggests that post-cardiac arrest care at [OHCA centres] is associated with improved outcomes at hospital discharge.’9

In summary, there remains considerable uncertainty regarding the effects of OHCA centres on survival following OHCA internationally, and in the setting of the National Health Service (NHS) in England. A change in practice of bypassing local hospitals in favour of OHCA centres would have considerable resource implications for hospitals and ambulance services. This study therefore addressed the question of whether patients with OHCA in England should be transported to the nearest hospital, or directly to an OHCA centre, and if certain subgroups might benefit more than others.

Section snippets

Methods

We undertook a retrospective analysis of cardiac arrest data in England, collected by the national Out-Of-Hospital Cardiac Arrest Outcomes Registry (OHCAO).10 Data from three participating ambulance trusts (South West, West Midlands and North West Ambulance Service) was available for a two-year period from January 2017 to December 2018 and included the following Utstein variables11

  • Patient’s age

  • Gender

  • Location of the event

  • Event witnessed by

  • First recorded cardiac rhythm

  • Bystander cardio-pulmonary

Results

During the two-year study period, 22,785 cases of OHCA were recorded in the three participating ambulance services. After application of inclusion and exclusion criteria and removing cases with missing data, 5805 cases of OHCA remained for the primary analysis. See Fig. 1 for the corresponding Utstein flowchart.

Of the 10,650 adult patients with OHCA of presumed cardiac origin who were transported to a hospital, 5375 (50.5%) were transported to one of 23 24/7 PPCI centres. When looking at

Discussion

This study shows that admission to an OHCA centre was associated with a small but statistically significant and clinically important absolute difference in survival to hospital discharge of approximately 2.5%. The effect size was very similar if an OHCA centre was defined as a hospital with 24/7 PPCI capability or one with over 100 OHCA admissions per year. This is likely due to the considerable overlap that exists between these categorisations; most 24/7 PPCI centres are also high-volume

Conclusions

Admission to an OHCA centre with 24/7 PPCI capability is associated with a 2.7% increase in survival to hospital discharge. This benefit is more pronounced in patients with OHCA due to VF, and at best minimal in patients with OHCA due to asystole. Based on our study and previous research, creating bypass criteria for OHCA patients with an initially shockable rhythm or PEA and pre-hospital ROSC would be expected to result in a moderate increase in resource utilisation at OHCA centres with 24/7

Conflict of interest

The authors have no conflict of interest to declare.

Authors contributions

JVVF and JB conceptualized the study. GDP curated the data, JVVF formally analysed the data and wrote the original draft of the paper. JB and GDP reviewed and edited the original draft. All authors approved the final version of the paper.

Data sharing agreement

Data for this analysis were provided by the Out-of-Hospital Cardiac Arrest Outcomes (OHCAO) registry via a data sharing agreement which excludes passing on data to third parties. We are therefore unable to makes these data available to others. Please refer to the OHCAO project website for information relating to data sharing requests:

https://warwick.ac.uk/fac/sci/med/research/ctu/trials/ohcao/health/data_sharing/.

Funding

The OHCAO registry is funded by the British Heart Foundation and Resuscitation Council UK. The registry is also supported by the National Institute for Health Research (NIHR) Applied Research Collaboration (ARC) West Midlands. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Acknowledgements

Data for this research were provided by the Out-of-Hospital Cardiac Arrest Outcomes (OHCAO) registry, hosted by the Clinical Trials Unit, University of Warwick Medical School. We want to thank all staff at OHCAO for their help with this research. We also want to express our gratitude to Dr Sarah Black and colleagues at the South Western Ambulance Service, Clare Bradley and colleagues at the North West Ambulance Service, and Jenny Lumley-Holmes and colleagues at the West Midlands Ambulance

References (27)

  • N. Nielsen et al.

    Targeted temperature management at 33 degrees C versus 36 degrees C after cardiac arrest

    N Engl J Med

    (2013)
  • K.B. Kern

    Usefulness of cardiac arrest centers - extending lifesaving post-resuscitation therapies: the Arizona experience

    Circulation

    (2015)
  • OHCA Steering Group

    Resuscitation to recovery: a national framework to improve care of people with out-of-hospital cardiac arrest (OHCA) in England

    (2017)
  • Cited by (15)

    View all citing articles on Scopus
    View full text