Clinical experience with dofetilide in the treatment of patients with atrial fibrillation

Introduction: Dofetilide is the newest drug approved by the United States Food and Drug Administration for the treatment of patients with atrial fibrillation (AF). Few data on the efficacy and safety of dofetilide in a diverse group of patients are available. The aim of this study was to evaluate the results of dofetilide in a consecutive series of 69 patients with AF. Methods and Results: Sixty-nine patients with persistent (n = 53) or paroxysmal (n = 16) AF were administered dofetilide in-hospital. Prior to starting dofetilide, all patients had been adequately anticoagulated, and concomitant agents contraindicated in the presence of dofetilide were discontinued. Heart rhythms were monitored continuously by telemetry in all patients. The initial dose, which was determined using the Cockroft-Gault calculated creatinine clearance, was 500 mug bid, 250 mug bid, and 125 mug bid in 51, 13, and 5 patients, respectively. Reductions in subsequent dosage occurred in 12 patients, 4 for QT prolongation. Dofetilide was discontinued in-hospital in 7 patients, 2 for adverse arrhythmic events and 3 for unacceptable QT prolongation. Twenty-seven (63%) of 43 patients in AF converted spontaneously to sinus rhythm. Fifty-eight patients were discharged receiving. dofetilide treatment and were followed as outpatients for 21 7 months. One third of patients continued to take dofetilide at I year. One patient had a cardiac arrest 1 day after hospital discharge. Conclusion: Dofetilide is a well-tolerated antiarrhythmic drug with a high conversion rate of AF to sinus rhythm. One third of patients maintained sinus rhythm at 1 year. Proarrhythmia can occur and initiation of therapy must be performed in-hospital.