# Long-term neurological outcome following out-of-hospital cardiac arrest in Switzerland: a single-centre observational study

## TL;DR

This study examines long-term neurological outcomes for cardiac arrest patients in Switzerland before and after introducing a new resuscitation method.

## Contribution

The study evaluates the impact of an extracorporeal cardiopulmonary resuscitation program on neurological outcomes in a Swiss hospital setting.

## Key findings

- Favorable neurological outcomes increased slightly after implementing the ECPR program.
- All ECPR-treated survivors had favorable neurological outcomes at one year.
- Factors like non-shockable rhythm and unwitnessed arrest were linked to lower survival rates.

## Abstract

Favourable neurological outcome in patients with out-of-hospital cardiac arrest (OHCA) vary across countries. Different advanced resuscitation strategies such as extracorporeal cardiopulmonary resuscitation (ECPR) might have impact on long-term neurological outcome. However, this remains unclear in Switzerland.

This retrospective single-centre observational study included all patients with OHCA transported by the local emergency medical services to a large Swiss academic hospital between 1 January 2015 and 31 December 2023. Data were collected before and after the implementation of the local ECPR programme for patients with refractory OHCA on 01 May 2018. The primary outcome was 1-year favourable neurological outcome, defined as Cerebral Performance Categories 1 and 2. Secondary outcomes included 30-day favourable neurological outcome, characteristics and survival of patients treated with ECPR, and factors associated with non-survival among all OHCA patients.

A total of 578 patients with OHCA were transported to the hospital. Favourable neurological survival at 1 year was 16.8% (95%-CI, 12.1–22.4%) before and 21.5% (95%-CI, 17.4–26.1%) after the ECPR programme implementation. Hazard ratios for overall survival were 2.19 for patients with a non-shockable initial rhythm, 1.02 for older age and 1.68 for unwitnessed OHCA. Of all transported patients, 16.8% (n = 97, n = 31 before vs. n = 66 after) met local ECPR criteria. In total 34 patients with refractory OHCA were treated with ECPR, all assessable survivors had favourable 1-year neurological outcomes.

This observational study on patients sustaining OHCA transferred to a large Swiss hospital showed 1 year favourable outcome in 19.7% (95%-CI: 16.6–23.2%). Among ECPR patients, all five survivors had a favourable neurological outcome at 1 year. No association was found between implementing an ECPR programme for patients with refractory OHCA and 1 year favourable neurological outcome. However, the effect might be underestimated given the low incidence of ECPR.

https://www.clinicaltrials.gov, identifier NCT03759210.