The Amsterdam Resuscitation Study (ARREST) is an ongoing, prospective registry of all-cause OHCA in the North Holland province of The Netherlands. ARREST was set up to establish the determinants of outcome of OHCA 8,9 and to gain insight in the genetic, clinical, andBackground-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 outof-hospital cardiac arrest has significantly increased, and, if so, whether this is attributable to AED use. Methods and 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.

Background— Atrial fibrillation (AF) is associated with sudden cardiac death. We aimed to study whether AF is associated with ventricular fibrillation (VF), the most common cause of sudden cardiac death and whether this association is independent of confounders, ie, concomitant disease, use of antiarrhythmic or QT-prolonging drugs, and acute myocardial infarction. Methods and Results— We performed a community-based case-control study. Cases were patients with out-of-hospital cardiac arrest because of ECG-documented VF. Controls were age-/sex-matched non-VF subjects from the community. VF risk in AF patients was studied by means of (conditional) logistic regression, adjusting for all available confounders. We studied 1397 VF cases and 3474 controls. AF occurred in 215 cases (15.4%) and 90 controls (2.6%). AF was associated with a 3-fold increased risk of VF (adjusted odds ratio, 3.1 [2.1–4.5]). VF risk in AF cases was increased to the same extent across all age/sex groups and in AF cases who had no comorbidity (adjusted odds ratio 3.0 [1.6–5.5]) or used no confounding drugs (antiarrhythmics, 2.4 [1.4–4.3]; QT-prolonging drugs, 3.1 [1.8–5.4]). VF risk was similarly increased in AF cases with acute myocardial infarction–related VF (adjusted odds ratio 2.6 [1.4–4.8]), and those with non-acute myocardial infarction–related VF (adjusted odds ratio 4.3 [1.9–10.1]). Conclusions— AF is independently associated with a 3-fold increased risk of VF. Comorbidity, use of antiarrhythmic or QT-prolonging drugs, or acute myocardial infarction does not fully account for this increased risk.