Bystander Efforts in Out-of-Hospital Cardiac Arrest

Study Questions:

What is the effect of bystander interventions on long-term functional outcomes among survivors of out-of-hospital cardiac arrest?


Using nationwide data in Denmark, the authors examined the risk of anoxic brain damage or nursing home admission among 30-day survivors of out-of-hospital cardiac arrest during a 1-year follow-up period. Outcomes were analyzed according to whether patients received bystander cardiopulmonary resuscitation (CPR) and bystander defibrillation, and temporal trends were analyzed for the years from 2001 to 2012.


Data on 2,855 patients were analyzed. A total of 10.5% had brain damage or were admitted to a nursing home and 9.7% died during the 1-year follow-up period. During the study period, among the 2,084 patients who had cardiac arrests that were not witnessed by emergency medical services personnel, the rate of bystander CPR increased from 66.7% to 80.6% (p < 0.001), the rate of bystander defibrillation increased from 2.1% to 16.8% (p < 0.001), the rate of brain damage or nursing home admission decreased from 10.0% to 7.6% (p < 0.001), and all-cause mortality decreased from 18.0% to 7.9% (p = 0.002). In adjusted analyses, bystander CPR was associated with a risk of brain damage or nursing home admission that was significantly lower than that associated with no bystander resuscitation (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.47-0.82), as well as a lower risk of death (HR, 0.70; 95% CI, 0.50-0.99) and a lower risk of the composite endpoint of brain damage, nursing home admission, or death (HR, 0.67; 95% CI, 0.53-0.84). The risks of these outcomes were even lower among patients who received bystander defibrillation as compared with no bystander resuscitation.


Bystander CPR and defibrillation were associated with risks of brain damage or nursing home admission and of death from any cause that were significantly lower than those associated with no bystander resuscitation.


The findings from this manuscript, and several others with shorter follow-up, indicate that bystander interventions can improve functional long-term outcomes. This underscores the need to focus on strategies that help bystanders initiate CPR and improve public access to automated external defibrillators. This report also shows a dramatic improvement in bystander CPR and defibrillation following systematic national efforts in CPR training and dissemination of automated external defibrillators and a link between these improvements and outcomes. Policymakers at all levels of government in the United States would be well served emulating the admirable Danish example.

Clinical Topics: Acute Coronary Syndromes, Arrhythmias and Clinical EP, Geriatric Cardiology, Heart Failure and Cardiomyopathies, Prevention, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure

Keywords: Acute Coronary Syndrome, Arrhythmias, Cardiac, Cardiopulmonary Resuscitation, Defibrillators, Electric Countershock, Emergency Medical Services, Geriatrics, Heart Arrest, Heart Failure, Hypoxia, Brain, Nursing Homes, Out-of-Hospital Cardiac Arrest, Primary Prevention, Survivors, Treatment Outcome

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