Trends in survival from out-of-hospital cardiac arrest with a shockable rhythm and its association with bystander resuscitation: a retrospective study

Objective: Over 300 000 cases of out-of-hospital cardiac arrests (OHCAs) occur each year in the USA and Europe. Despite decades of investment and research, survival remains disappointingly low. We report the trends in survival after a ventricular fibrillation/pulseless ventricular tachycardia OHCA, over a 13-year period, in a French urban region, and describe the simultaneous evolution of the rescue system.

Methods: We investigated four 18-month periods between 2005 and 2018. The first period was considered baseline and included patients from the randomised controlled trial 'DEFI 2005'. The three following periods were based on the Paris Sudden Death Expertise Center Registry (France). Inclusion criteria were non-traumatic cardiac arrests treated with at least one external electric shock with an automated external defibrillator from the basic life support team and resuscitated by a physician-staffed ALS team. Primary outcome was survival at hospital discharge with a good neurological outcome.

Results: Of 21 781 patients under consideration, 3476 (16%) met the inclusion criteria. Over all study periods, survival at hospital discharge increased from 12% in 2005 to 25% in 2018 (p<0.001), and return of spontaneous circulation at hospital admission increased from 43% to 58% (p=0.004).Lay-rescuer cardiopulmonary resuscitation (CPR) and telephone CPR (T-CPR) rates increased significantly, but public defibrillator use remained limited.

Conclusion: In a two-tiered rescue system, survival from OHCA at hospital discharge doubled over a 13-year study period. Concomitantly, the system implemented an OHCA patient registry and increased T-CPR frequency, despite a consistently low rate of public defibrillator use.