Improved survival after out-of-hospital cardiac arrest and use of automated external defibrillators.
BACKGROUND
In recent years, a wider use of automated external defibrillators (AEDs) to treat out-of-hospital cardiac arrest was advocated in The Netherlands. We aimed to establish whether survival with favorable neurologic outcome after out-of-hospital cardiac arrest has significantly increased, and, if so, whether this is attributable to AED use.


RESULTS
We performed a population-based cohort study, including patients with out-of-hospital cardiac arrest from cardiac causes between 2006 and 2012, excluding emergency medical service-witnessed arrests. We determined survival status at each stage (to emergency department, to admission, and to discharge) and examined temporal trends using logistic regression analysis with year of resuscitation as an independent variable. By adding each covariable subsequently to the regression model, we investigated their impact on the odds ratio of year of resuscitation. Analyses were performed according to initial rhythm (shockable versus nonshockable) and AED use. Rates of survival with favorable neurologic outcome after out-of-hospital cardiac arrest increased significantly (N=6133, 16.2% to 19.7%; P for trend=0.021), although solely in patients presenting with a shockable initial rhythm (N=2823; 29.1% to 41.4%; P for trend<0.001). In this group, survival increased at each stage but was strongest in the prehospital phase (odds ratio, 1.11 [95% CI, 1.06-1.16]). Rates of AED use almost tripled during the study period (21.4% to 59.3%; P for trend <0.001), thereby decreasing time from emergency call to defibrillation-device connection (median, 9.9 to 8.0 minutes; P<0.001). AED use statistically explained increased survival with favorable neurologic outcome by decreasing the odds ratio of year of resuscitation to a nonsignificant 1.04.


CONCLUSIONS
Increased AED use is associated with increased survival in patients with a shockable initial rhythm. We recommend continuous efforts to introduce or extend AED programs.
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Marieke T
MT
Blom
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Stefanie G
SG
Beesems
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Petronella C M
PC
Homma
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Jolande A
JA
Zijlstra
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Michiel
M
Hulleman
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Daniel A
DA
van Hoeijen
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Abdennasser
A
Bardai
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Jan G P
JG
Tijssen
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.). h.l.tan@amc.uva.nl.
Hanno L
HL
Tan
From the Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (M.T.B., S.G.B., P.C.M.H., J.A.Z., M.H., D.A.v.H., A.B., J.G.P.T., H.L.T., R.W.K.); Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands (A.B.).
Rudolph W
RW
Koster
D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D047548:Defibrillators / Q000706:statistics & numerical data* / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies; D015996:Survival Rate / Q000639:trends
defibrillators; epidemiology; resuscitation; survival