Purpose: The majority of out-of-hospital cardiac arrest (OHCA) registries provide a follow-up limited at 1 month, so the subsequent survival remains an unexplored challenge. We sought to evaluate the long-term outcome after OHCA via an Utstein-based cardiac arrest registry.
Methods: We enrolled in the Cardiac Arrest Registry of the Province of Pavia (about 550000 inhabitants in northern Italy) all the patients who suffered an OHCA from any aetiology in whom CPR was attempted. The primary endpoint was the survival at 1 month, and the secondary endpoints were the survival at 6 months and then every year until 5 years after OHCA.
Results: 1774 resuscitation attempts for confirmed OHCAs were collected in the first 45 months (October 2014-June 2018). 59.7% of the patients were males with a mean age of 73.4 ± 16 years. The mean EMS response time was 11:31 ± 5:09 mins. The vast majority of OHCA occurs at home (78.8%) with a medical etiology (93%). A bystander witnessed the event in 56.1% and the EMS in 15.6%. Bystander CPR rate was 39.5%, whilst an AED was used before EMS in 2.5%. The first rhythm was shockable in 18.2% (90.7% VF, 2.5% VT without pulse, 6.8% AED shockable). Survival was significantly higher for shockable Utstein categories (p<0.01) both when considering survival from the event (left panel) and from hospital discharge (right panel). Interestingly, survival continued to decrease also in shockable rhythm categories over time, from 90% in the first year to about 80% at four years.
Conclusions:  OHCA with shockable rhythm showed a better survival both from the event and from hospital discharge. However, our results demonstrated that survival after OHCA can change over the time in all the Utstein categories, so we believe that a longer follow-up should be encouraged by next Utstein style revision.

5 - Long-term survival after an out-of-hospital cardiac arrest. An Utstein-based analysis