Abstract 4035: Incidence and Outcomes of Out-of-Hospital Cardiac Arrest with Shock-resistant Ventricular Fibrillation in Osaka: Data from a Large-scaled Population-based Cohort
Objectives: We aimed to evaluate the temporal trends of incidence and outcomes of out-of-hospital cardiac arrest (OHCA) with shock-resistant ventricular fibrillation (VF) based on a large-scaled population-based cohort study.
Methods: We enrolled all persons aged 18 years or more who suffered OHCA of presumed cardiac etiology, were witnessed by bystanders, and were treated by emergency medical service (EMS) in Osaka Prefecture (population, 8.8 million), Japan from May 1st 1998 through Dec 31th 2006. Data were prospectively collected by EMS personnel using an Utstein-style database. We evaluated the temporal trends of incidence and outcomes of the OHCA who had an initial rhythm of VF which persisted during resuscitation efforts before hospital arrival. In this study, we defined these persistent VF as shock-resistant VF.
Results: During the study period, there were 8782 witnessed OHCA cases of cardiac etiology. Among them, 1733 had VF as initial rhythm and 468 of which was shock-resistant. While the annual incidence (per 100000 population) of witnessed OHCA of cardiac etiology increased from 13.2 to 16.4, that of shock-resistant VF decreased from 0.9 to 0.8. The proportion of shock-resistant VF among witnessed VF cardiac arrests decreased from 41% to 20% (Table⇓). Neurologically favorable one-month survival from witnessed VF increased from 6.1% to 16.5%. Survival after shock-resistant VF has been improved, but neurologically favorable outcome at one-month remained 6.9% in 2006.
Conclusion: Although the incidence of shock-resistant VF has decreased and survival from witnessed VF cardiac arrests has increased, survival outcome from shock-resistant VF is still poor.