Characteristics and outcomes of out-of-hospital cardiac arrest cases responded by emergency medical services across three states in Malaysia

INTRODUCTION: IOut-of-hospital cardiac arrest (OHCA) is globally a critical, time-sensitive emergency with varying outcomes. In Asia, the Pan Asian Resuscitation Outcome Study reported survival rates between 0.5% to 8.5%. We aim to describe the characteristics and outcomes of OHCA cases responded to by Emergency Medical Services (EMS) across several cities in Sarawak, Penang and Klang Valley in Malaysia.

MATERIALS AND METHODS: This retrospective observational study analysed EMS data from Sarawak, Penang and Klang Valley from 2010 to 2019. All OHCA cases where EMS performed cardiopulmonary resuscitation (CPR) were included, regardless of age or aetiology. The primary outcome was survival to hospital admission with the secondary outcome a return of spontaneous circulation (ROSC) prior to Emergency Department arrival.

RESULTS: A total of 2,435 OHCA cases were analysed. Median patient age was 58 years, 70% of them are male with 63% had underlying medical conditions, with hypertension being the most common. Out of all cases, 71% of arrests occurred at home, 60% witnessed. Median time from arrest to 999 call was 20 minutes, median time for ambulance arrival thereafter is 17 minutes. Bystander CPR rate was 38%, bystander Automated External Defibrillator (AED) use 1.5- 2.6%. Detection of shockable rhythm on first analysis by EMS was 3.9 to 7.7%. Overall survival to admission rate was 4.76%. ROSC rate before Emergency Department arrival was 2.8%. Survival to admission among bystander-witnessed arrests with shockable rhythm was 14.7%.

CONCLUSION: Survival to admission rates for OHCA patients in the studied Malaysian regions (1.3-6.7%) are lower compared to some Asian countries. Areas for improvement include reducing time from arrest to 999 calls, decreasing time to EMS arrival, and increasing bystander CPR and AED use rates. Implementing the Utstein ten-step implementation strategy, focusing on community-based interventions and improving EMS response, could potentially enhance survival rates in Malaysia.