Efficacy and safety of dofetilide in patients with atrial fibrillation and atrial flutter.
BACKGROUND
Dofetilide, an I(Kr) blocker has been demonstrated to be effective in terminating persistent atrial fibrillation and flutter (AF/AFL), and in maintaining sinus rhythm after direct current cardioversion (CV). It is not known, however, whether pharmacological conversion with dofetilide predicts maintenance of sinus rhythm. In addition, there is limited information comparing the efficacy of dofetilide in persistent versus paroxysmal AF/AFL.


RESULTS
Eighty consecutive patients with AF/AFL (51 persistent, 29 paroxysmal) admitted for initiation of dofetilide were studied. Termination of persistent AF/AFL occurred in 61% of patients while 39% required CV. After 21 +/- 19 months of follow-up, 37% of patients with persistent AF/AFL were free of recurrence. Acute conversion with dofetilide did not predict long term efficacy. Dofetilide was more effective in maintaining sinus rhythm in patients with AFL (65%) than in those with AF (25%) (p < 0.05). Dofetilide was more likely to maintain sinus rhythm in patients with persistent than paroxysmal AF/AFL (37 vs. 14%; p < 0.05). Torsades de Pointes developed in two patients despite careful dosing and monitoring of QT changes.


CONCLUSIONS
Dofetilide is more effective in patients with persistent than in those with paroxysmal AF/AFL. Importantly, short-term response does not necessarily predict long-term efficacy. Significant proarrhythmia can occur even with careful in-hospital monitoring.
Banchs
Javier E
JE
Penn State Heart and Vascular Institute, Milton S. Hershey Medical Center, Penn State University, 500 University Drive, P.O. Box 850, Hershey, PA, 17033-0850, USA, jbanchs@psu.edu
Wolbrette
Deborah L
DL
Samii
Soraya M
SM
Penny-Peterson
Erica D
ED
Patel
Parag P
PP
Young
Sallie K
SK
Gonzalez
Mario D
MD
Naccarelli
Gerald V
GV
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology; D001282:Atrial Flutter / Q000188:drug therapy* / Q000503:physiopathology; D016009:Chi-Square Distribution; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010627:Phenethylamines / Q000627:therapeutic use*; D013449:Sulfonamides / Q000627:therapeutic use*; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D010627:Phenethylamines; D013449:Sulfonamides; C063533:dofetilide