Abstract 203: Patterns of Dofetilide Use for the Treatment of Atrial Fibrillation

Abstract

Introduction: Dofetilide is a costly medication that requires hospitalization at initiation. Patterns of dofetilide use for the control of atrial fibrillation (AF) have not been reported. We sought to determine what percentage of dofetilide initiations at our institution were concordant with the tiered maintenance of sinus rhythm (MSR) algorithm for anti-arrhythmic drug (AAD) use outlined in the AHA/HRS guidelines for the management of AF. Methods: We performed a chart review of consecutive patients admitted for dofetilide initiation at our institution from 2004-09. Follow-up data were collected through November 2012. Patients were classified to mirror the MSR algorithm. Results: A total of 122 patients were included. The mean age was 62±13 years. The mean ejection fraction was 50% ± 12% and the average baseline sinus rate was 62±11bpm. Within the MSR classification, 36 patients had no significant structural heart disease, 12 had hypertension without LVH, 16 had hypertension with LVH, 18 had CAD without CHF, and 40 had CHF. In patients with no prior AAD exposure [56/122 (46%)], dofetilide use was significantly more discordant with the MSR guidelines than for patients in whom dofetilide was used as a second line agent [46% discordant vs 15% discordant, p<0.001]. Eighty patients were in AF at the time of admission; rates of chemical cardioversion with dofetilide were significantly higher among patients in whom it was used as a second-line agent (53% vs 29%, p = 0.026). The average duration of dofetilide therapy for patients in whom dofetilide was their first AAD was 787 days. Rates of discontinuation of dofetilide during the initial admission (due to ventricular arrhythmia or excessive QT prolongation) were similar between the AAD naïve (18%) and second-line (20%) cohorts. Conclusions: A significant percentage of dofetilide use for the control of AF is as first-line AAD therapy. Electrophysiologists appear to be basing their choice of AAD on patient specific factors, such as baseline bradycardia, rather than the MSR algorithm. Given that the average duration of dofetilide therapy was little more than 2 years in AAD naïve patients, the cost-effectiveness of hospitalizing patients for dofetilide loading as a first line agent for the control of AF warrants further examination.