Allied Professionals (Non-physician submissions only) -> Clinical Research D-AB01 - The Wide Spectrum of Arrhythmia Care: EP Procedure to Follow-up (ID 24) Abstract

D-AB01-04 - Observations During Re-initiation Of Dofetilide After Atrial Fibrillation Ablation: Implications For Monitoring And Duration Of Hospitalization (ID 759)

 S. Isaac: Nothing relevant to disclose.


Background: Dofetilide (DOF) is typically held for ~ 5 doses prior to and resumed post AF ablation (PVI) at the previously tolerated dose. ECG monitoring for QT prolongation and torsades de points (TdP) is recommended with DOF re-initiation but prolongs the hospitalization and is of unclear benefit.
Objective: Determine the incidence and dose related timing of ↑QT requiring dose adjustments or producing TdP with re-initiation of DOF immediately after PVI.
Methods: Chart review of 756 patients undergoing PVI from July 2018 through July 2019 identified 68 (9%) patients who held, median 5 doses, of DOF prior to PVI. Baseline DOF dosing before PVI did not produce ↑QTc. DOF was restarted on the evening post-procedure at pre-procedure dose and 12 lead ECGs were obtained at baseline and 2 hours after each dose. The number of DOF doses given prior to discharge was based on physician preference and/or evidence of QT increase >500ms but always included at least 2 doses.
Results: Of the 68 patients, 4 (5.8%) had ↑QTc resulting in DOF dose reduction but no TdP. The maximum QTc in these 4 patients was 503 to 523 ms; DOF dose reduction decreased the QTC. All episodes of QTc >500ms occurred after the 1st or 2nd DOF dose including in the 42 (62%) patients who remained hospitalized for the full reload. The 26 patients (38%) who had QTc monitoring for only 2 -3 doses after re-initiation without QT prolongation had no late TdP or QT increase on ECG monitoring after discharge or at follow-up. The basis for the QT prolongation could not be determined in the 4 patients, with no known other QT prolonging drugs or electrolyte disturbance.
Conclusion: When restarting DOF after PVI, a small number of patients (5.8%) had modest QTc prolongation necessitating dose adjustment of DOF from previously tolerated dose. The QTc prolongation was noted after the 1st and 2nd doses of restart and was easily managed by dose reduction without TdP. These data, if confirmed in a larger study population, suggest that an abbreviated QTc ECG monitoring period that can shorten average hospitalization by a day may be appropriate for DOF re-initiation post PVI.