title: Relapse and mortality following cardioversion of new-onset vs. recurrent atrial fibrillation and atrial flutter in the elderly.
abstract: OBJECTIVE
  Trials of rate control vs. rhythm control for atrial fibrillation or flutter included few patients with new-onset arrhythmia. Our objective was to assess the relapse rate and the effect of the relapse of new-onset atrial arrhythmias on mortality after direct-current cardioversion (DCCV).
  
  
  RESULTS
  A cohort of 351 patients with atrial fibrillation (new onset in 179) and 126 patients with atrial flutter (new onset in 78) was followed-up after DCCV. Cox proportional hazard models were used. Median age was 74.6 years. Mean follow-up for relapse was 7.7 months; for death, 29.4 months. Patients with new-onset atrial flutter [adjusted hazard ratio (HR) = 1] were more likely to maintain sinus rhythm than the patients with recurrent atrial flutter (adjusted HR = 2.5, P < 0.01), new-onset atrial fibrillation (adjusted HR = 2.4, P < 0.01), or recurrent atrial fibrillation (adjusted HR = 2.7, P < 0.01). Patients with new-onset atrial fibrillation were as likely to have relapses as patients with recurrent atrial fibrillation or flutter. Relapse of atrial arrhythmia after DCCV was associated with increased mortality (adjusted HR= 3.1, P < 0.01).
  
  
  CONCLUSIONS
  DCCV is more successful in maintaining sinus rhythm in patients with new-onset atrial flutter than in patients with new-onset atrial fibrillation. Relapse of atrial arrhythmia after cardioversion is associated with increased mortality.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Ahmad A
authors.initials: AA
authors.lastname: Elesber
authors.forename: Ana Gabriela
authors.initials: AG
authors.lastname: Rosales
authors.forename: Regina M
authors.initials: RM
authors.lastname: Herges
authors.forename: Win-Kuang
authors.initials: WK
authors.lastname: Shen
authors.forename: Brenda S
authors.initials: BS
authors.lastname: Moon
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Malouf
authors.forename: Naser M
authors.initials: NM
authors.lastname: Ammash
authors.forename: Virend
authors.initials: V
authors.lastname: Somers
authors.forename: David O
authors.initials: DO
authors.lastname: Hodge
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hammill
authors.forename: Paul A
authors.initials: PA
authors.lastname: Friedman
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000401:mortality / Q000628:therapy*; D001282:Atrial Flutter / Q000401:mortality / Q000628:therapy*; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012008:Recurrence; D016019:Survival Analysis