Efficacy and safety of dofetilide, a new class III antiarrhythmic agent, in acute termination of atrial fibrillation or flutter after coronary artery bypass surgery. Dofetilide Post-CABG Study Group.
Ninety-eight patients, who developed atrial fibrillation/flutter after coronary artery bypass grafting within 1-6 days after surgery, were included into a double-blind, placebo-controlled, randomized trial to assess the efficacy and safety of dofetilide. Patients were randomly allocated to dofetilide 4 micrograms/kg i.v. (n = 33), dofetilide 8 micrograms/kg i.v. (n = 32) or placebo (n = 33) given intravenously over 15 min at a constant infusion rate. Responders were defined as patients who converted to sinus rhythm at any time during the initial 3 h after the start of the infusion. The conversion rates were 24% (8/33) on placebo, 36% (12/33) on dofetilide 4 micrograms/kg, and 44% (14/32) on dofetilide 8 micrograms/kg. The P-values (two-tailed) were 0.27 for dofetilide 4 micrograms/kg vs. placebo, 0.11 for dofetilide 8 micrograms/kg vs. placebo, and 0.10 for dose-response relationship. Short episodes of aberrant ventricular conduction and ventricular tachycardia were seen separately in three subjects after dofetilide 8 micrograms/kg. No episodes of torsades de pointes were noted. No negative inotropic effect was noted. In conclusion, dofetilide was well tolerated, but the effects on atrial fibrillation/flutter did not attain statistical significance, possibly due to the high placebo conversion rate.
Frost
L
L
Department of Cardiology, Skejby Sygehus, University Hospital, Aarhus, Denmark.
Mortensen
P E
PE
Tingleff
J
J
Platou
E S
ES
Christiansen
E H
EH
Christiansen
N
N
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000209:etiology; D001282:Atrial Flutter / Q000188:drug therapy* / Q000209:etiology; D016001:Confidence Intervals; D001026:Coronary Artery Bypass; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010627:Phenethylamines / Q000627:therapeutic use*; D015990:Placebo Effect; D011183:Postoperative Complications / Q000188:drug therapy*; D018401:Sample Size; D013449:Sulfonamides / Q000627:therapeutic use*; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D010627:Phenethylamines; D013449:Sulfonamides; C063533:dofetilide