Efficacy of Dofetilide in the Treatment of Atrial Fibrillation-Flutter in Patients With Reduced Left Ventricular Function. A Danish Investigation of Arrhythmia and Mortality On Dofetilide (DIAMOND) Substudy - DIAMOND Low Ejection Fraction Substudy
Efficacy of Dofetilide in the Treatment of Atrial Fibrillation-Flutter in Patients With Reduced Left Ventricular Function. A Danish Investigation of Arrhythmia and Mortality On Dofetilide (DIAMOND) Substudy.
What is the efficacy of dofetilide in restoring and maintaining sinus rhythm in patients with a low ejection fraction (EF), and does restoration of sinus rhythm affect survival?
Patients Enrolled: 506
Mean Follow Up: 1 year
There were 506 patients with atrial fibrillation/flutter (AF/Fl), congestive heart failure (CHF) or recent myocardial infarction (MI) and an EF <0.35. These patients received either dofetilide or placebo in a multicenter, randomized, double-blinded trial. Electrical cardioversion was encouraged if AF/Fl was present after 1 month of treatment. The minimum follow-up was 1 year.
Dofetilide and placebo were used in 249 and 257 patients, respectively. Pharmacologic or spontaneous cardioversion occurred in 44% of the dofetilide group, compared to 14% of the placebo group. Including electrical cardioversion, sinus rhythm was restored in 59% and 34% of the dofetilide- and placebo-treated groups. One year after cardioversion, sinus rhythm was still present in 79% of the dofetilide group, compared to 42% of the placebo group. Overall mortality was the same in the dofetilide and placebo groups. In both groups, sinus rhythm was associated with lower mortality than AF/Fl (relative risk 0.44). The probability of hospitalizations was lower in the dofetilide group (relative risk 0.7). Nonfatal torsade de pointes occurred in 1.6% of patients treated with dofetilide.
Dofetilide is more effective than placebo in restoring and maintaining sinus rhythm in patients with AF/Fl and a low EF. Regardless of the method by which sinus rhythm is restored, successful maintenance of sinus rhythm results in improved survival.
This study demonstrates that dofetilide is a safe alternative to amiodarone among patients with CHF or a recent MI who have AF/Fl. Furthermore, this is the largest study to date demonstrating the survival advantage of sinus rhythm among patients with AF/Fl and left ventricular dysfunction.
1. Pedersen OD, Bagger H, Keller N, et al. for the Danish Investigations of Arrhythmia and Mortality ON Dofetilide Study Group. Circulation 2001;104:292-6.
Keywords: Risk, Myocardial Infarction, Follow-Up Studies, Potassium Channel Blockers, Electric Countershock, Phenethylamines, Torsades de Pointes, Heart Failure, Ventricular Dysfunction, Left, Sulfonamides, Atrial Flutter
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