Author + information
- Stephen Wang,
- Terrence Welch,
- Rajbir Sangha,
- Robert Maloney and
- Aaron Kaplan
Background: Dofetilide is used to treat patients with atrial fibrillation, with recommended dosing based on the Cockcroft-Gault formula using actual body weight (ABW). Dose reduction or discontinuation may be necessary for excessive QT prolongation. We investigated whether initial dosing based on ideal body weight (IBW) may reduce the need for subsequent dose reduction or discontinuation.
Methods: We conducted a retrospective review of 189 patients admitted to an academic medical center for initiation of dofetilide. Dosing was originally calculated based on ABW, and was recalculated using IBW. Patients who would have received a reduced dose based on IBW (Reduced Dose Group) were compared to patients whose dose would not have changed based on IBW (Same Dose Group). Manual measurement of QT intervals was performed, then normalized with Bazett's correction.
Results: 29% (54/189) of patients would have received a lower initial dose of dofetilide based on IBW. Patients in the Reduced Dose Group had more drug discontinuations or dose reductions (P=0.027), a greater peak QTc (P=0.020), and a greater frequency of peak QTc ≥ 500ms (p=0.026) compared to the Same Dose Group. No statistical difference was observed in absolute QTc change.
Conclusions: This study suggests that dofetilide dosing using ideal body weight, as opposed to actual body weight (as currently recommended), may lead to fewer dose reductions or discontinuations, may yield a lower peak QTc, and may less frequently prolong the QTc to ≥ 500ms.
Poster Hall, Hall C
Friday, March 17, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Arrhythmias and Clinical EP: AF Ablation
Abstract Category: 6. Arrhythmias and Clinical EP: Other
Presentation Number: 1150-093
- 2017 American College of Cardiology Foundation