Pulseless electrical activity is associated with improved survival in out-of-hospital cardiac arrest with initial non-shockable rhythm

Objective: To describe the prevalence, baseline characteristics and factors associated with survival in out-of-hospital cardiac arrest (OHCA) with initial non-shockable rhythm sub-grouped into pulseless electrical activity (PEA) and asystole as presenting rhythm. Methods: The Swedish Registry of Cardiopulmonary Resuscitation is a prospectively recorded nationwide registry of modified Utstein parameters, including all patients with attempted resuscitation after OHCA. Data between 1990-2016 were analyzed. Results: After exclusions, the study population consisted of 48,707 patients presenting with either PEA or asystole. The proportion of PEA increased from 12% to 22% during the study period with a fivefold increase in 30-day survival reaching 4.9%. Survival in asystole showed a modest increase from 0.6% to 1.3%. In the multivariable analysis, PEA was independently associated with survival at 30 days (OR 1.54, 95% CI 1.26-1.88). Conclusion: Between 1990 and 2016, the proportion of PEA as the first recorded rhythm doubled with a fivefold increase in 30-day survival, while survival among patients with asystole remained at low levels. PEA and asystole should be considered separate entities in clinical decision-making and be reported separately in observational studies and clinical trials.