title: A randomized placebo-controlled trial of pre-treatment and short- or long-term maintenance therapy with amiodarone supporting DC cardioversion for persistent atrial fibrillation.
abstract: OBJECTIVE
  The efficacy of cardioversion (DCCV) for restoration of sinus rhythm (SR) in persistent atrial fibrillation (AF) is limited by a high relapse rate. Relapse may be reduced by amiodarone but no placebo-controlled trials of efficacy have been performed and the appropriate duration of therapy is unknown.
  
  
  RESULTS
  In this double-blind study, 161 subjects with persistent AF were randomized to one of three groups-placebo (n=38); amiodarone 400mg BD for 2 weeks prior to DCCV and 200mg daily for 8 weeks followed by placebo for 44 weeks (n=62, short-term amiodarone); amiodarone 400mg BD for 2 weeks then 200mg daily for 52 weeks (n=61, long-term amiodarone). Spontaneous reversion to SR occurred before DCCV in 21% (26/123) patients on amiodarone and none of the 38 patients on placebo (absolute difference 21%, 95% confidence interval (CI): 10 to 29%, P=0.002). At 8 weeks following DCCV, 51% (63/123) patients on amiodarone remained in SR compared to 16% (6/38) taking placebo (difference-35% 95% CI: -48 to -18%, P<0.001). At 1 year, 49% (30/61) patients on long-term amiodarone were in SR compared to 33% (21/62) taking short-term amiodarone (difference-15%, 95% CI: -31 to 2%, P=0.085). There was no difference in adverse event rate or quality of life scores between groups.
  
  
  CONCLUSIONS
  Amiodarone pre-treatment before electrical DCCV for persistent AF allows chemical conversion in one-fifth of patients without altering the efficacy of subsequent DC conversion. Amiodarone is more effective than placebo in the maintenance of SR when continued for 8 weeks following successful DCCV. More patients taking long-term amiodarone remained in SR at 52 weeks, but more had serious adverse effects requiring discontinuation of therapy. Eight weeks of adjuvant therapy with amiodarone following successful DCCV may be the preferred option.
authors.affiliation: Royal Hallamshire Hospital, Sheffield, UK. Kevin.channer@sth.nhs.uk
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Channer
authors.forename: Andrew
authors.initials: A
authors.lastname: Birchall
authors.forename: Richard P
authors.initials: RP
authors.lastname: Steeds
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Walters
authors.forename: Wilf W
authors.initials: WW
authors.lastname: Yeo
authors.forename: John N
authors.initials: JN
authors.lastname: West
authors.forename: Rangasamy
authors.initials: R
authors.lastname: Muthusamy
authors.forename: Walter E
authors.initials: WE
authors.lastname: Rhoden
authors.forename: Basil T
authors.initials: BT
authors.lastname: Saeed
authors.forename: Phillip
authors.initials: P
authors.lastname: Batin
authors.forename: W Paul
authors.initials: WP
authors.lastname: Brooksby
authors.forename: Ian
authors.initials: I
authors.lastname: Wilson
authors.forename: Simon
authors.initials: S
authors.lastname: Grant
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000009:adverse effects / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000628:therapy*; D003131:Combined Modality Therapy; D004311:Double-Blind Method; D004554:Electric Countershock / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011788:Quality of Life
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone