title: In-hospital versus out-of-hospital presentation of life-threatening ventricular arrhythmias predicts survival: results from the AVID Registry. Antiarrhythmics Versus Implantable Defibrillators.
abstract: OBJECTIVE
  This study describes the outcomes of patients from the Antiarrhythmics Versus Implantable Defibrillators (AVID) Study Registry to determine how the location of ventricular arrhythmia presentation influences survival.
  
  
  BACKGROUND
  Most studies of cardiac arrest report outcome following out-of-hospital resuscitation. In contrast, there are minimal data on long-term outcome following in-hospital cardiac arrest.
  
  
  METHODS
  The AVID Study was a multicenter, randomized comparison of drug and defibrillator strategies to treat life-threatening ventricular arrhythmias. A Registry was maintained of all patients with sustained ventricular arrhythmias at each study site. The present study includes patients who had AVID-eligible arrhythmias, both randomized and not randomized. Patients with in-hospital and out-of-hospital presentations are compared. Data on long-term mortality were obtained through the National Death Index.
  
  
  RESULTS
  The unadjusted mortality rates at one- and two-year follow-ups were 23% and 31.1% for patients with in-hospital presentations, and 10.5% and 16.8% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted mortality rates at one- and two-year follow-ups were 14.8% and 20.9% for patients with in-hospital presentations, and 8.4% and 14.1% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted long-term relative risk for in-hospital versus out-of-hospital presentation was 1.6 (95% confidence interval [CI] 1.3-1.9).
  
  
  CONCLUSIONS
  Compared with patients with out-of-hospital presentations of life-threatening ventricular arrhythmias not due to a reversible cause, patients with in-hospital presentations have a worse long-term prognosis. Because location of ventricular arrhythmia presentation is an independent predictor of long-term outcome, it should be considered as an element of risk stratification and when planning clinical trials.
authors.affiliation: Department of Medicine, the University of Alabama at Birmingham, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Epstein
authors.forename: J
authors.initials: J
authors.lastname: Powell
authors.forename: Q
authors.initials: Q
authors.lastname: Yao
authors.forename: C
authors.initials: C
authors.lastname: Ocampo
authors.forename: S
authors.initials: S
authors.lastname: Lancaster
authors.forename: Y
authors.initials: Y
authors.lastname: Rosenberg
authors.forename: D S
authors.initials: DS
authors.lastname: Cannom
authors.forename: J M
authors.initials: JM
authors.lastname: Herre
authors.forename: H L
authors.initials: HL
authors.lastname: Greene
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D016887:Cardiopulmonary Resuscitation; D017147:Defibrillators, Implantable; D004632:Emergency Medical Services; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D012042:Registries; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome; D014481:United States; D014693:Ventricular Fibrillation / Q000401:mortality / Q000628:therapy*
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone