Background
The effect of bystander interventions on long-term functional outcomes among survivors of out-of-hospital cardiac arrest has not been extensively studied.
Methods
We linked nationwide data on out-of-hospital cardiac arrests in Denmark to functional outcome data and reported the 1-year risks of anoxic brain damage or nursing home admission and of death from any cause among patients who survived to day 30 after an out-of-hospital cardiac arrest. We analyzed risks according to whether bystander cardiopulmonary resuscitation (CPR) or defibrillation was performed and evaluated temporal changes in bystander interventions and outcomes.
Results
Among the 2855 patients who were 30-day survivors of an out-of-hospital cardiac arrest during the period from 2001 through 2012, 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 2084 patients who had cardiac arrests that were not witnessed by emergency medical services (EMS) 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, 0.62; 95% confidence interval [CI], 0.47 to 0.82), as well as a lower risk of death from any cause (hazard ratio, 0.70; 95% CI, 0.50 to 0.99) and a lower risk of the composite end point of brain damage, nursing home admission, or death (hazard ratio, 0.67; 95% CI, 0.53 to 0.84). The risks of these outcomes were even lower among patients who received bystander defibrillation as compared with no bystander resuscitation.
Conclusions
In our study, we found that 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. (Funded by TrygFonden and the Danish Heart Foundation.)
Supported by the Danish foundation TrygFonden and the Danish Heart Foundation. The Danish Cardiac Arrest Registry is supported by TrygFonden.
Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.
Dr. Kragholm reports receiving lecture fees from Novartis Healthcare; Dr. Gislason, receiving grant support from Bayer, Pfizer, Boehringer Ingelheim, Bristol-Myers Squibb, and AstraZeneca; Dr. Køber, receiving lecture fees from Novartis and Sanofi; Dr. Torp-Pedersen, receiving grant support and lecture fees from Bayer and grant support from Biotronik; and Dr. Rasmussen, receiving grant support from Ferring. No other potential conflict of interest relevant to this article was reported.
We thank the emergency medical service personnel who completed the case-report forms for the Danish Cardiac Arrest Registry.
Source Information
From the Departments of Anesthesiology and Intensive Care Medicine (K.K., B.S.R.), Clinical Epidemiology (R.N.M., S.M.H., C.T.-P.), Cardiothoracic Surgery (K.T.), Social Medicine (K.F.), and Cardiology (S.E.J.), Aalborg University Hospital, and the Departments of Clinical Medicine (K.K., B.S.R.) and Health Science and Technology (S.M.H., K.F., S.E.J., C.T.-P., B.S.R.), Aalborg University, Aalborg, the Clinical Institute of Medicine, Aarhus University, Aarhus (K.K., B.S.R.), and the Departments of Clinical Physiology, Nuclear Medicine and PET (M.W.), and Cardiology (L.K.), Rigshospitalet, Copenhagen University Hospital, Emergency Medical Services Copenhagen and University of Copenhagen (M.W., F.L., F.F.), the Department of Cardiology, Copenhagen University Hospital Gentofte (C.M.H., S.R., F.F., G.G.), the National Institute of Public Health, University of Southern Denmark (G.G.), and the Department of Biostatistics, University of Copenhagen (T.A.G.), Copenhagen — all in Denmark; and Duke Clinical Research Institute, Durham, NC (C.M.H.).
Address reprint requests to Dr. Kragholm at the Department of Anesthesiology and Intensive Care Medicine, Aalborg University Hospital, Sdr. Skovvej 15, 9000 Aalborg, Denmark, or at [email protected].