Arrhythmias & electrophysiologyCohort study
Safety of Dofetilide Initiation Following a Shortened Amiodarone Washout Period
- cohort
Authors' conclusion
In this cohort, dofetilide initiation within 90 days of amiodarone discontinuation was not associated with TdP during inpatient loading, supporting the feasibility of monitored, expedited transitions in select patients.
Study context
- Population
- Mayo Clinic patients transitioned from amiodarone to dofetilide in <90 days with ≥12 weeks of amiodarone therapy and serum concentration ≥0.3 mcg/mL if measuredfinal cohort
- Participants
- 66 patients
- Exposure
- ≤30- vs >30-day transitions
- ≤30-day transitionsn = 16
- Outcome
- ventricular arrhythmias requiring dofetilide discontinuation
Further findings
Baseline characteristics
- mean age
- 65 ± 14 years
- men
- 74.2%
- paroxysmal
- 33.3%
- persistent
- 54.5%
- long-standing persistent
- 12.1%
- implantable cardioverter-defibrillators
- 22.7%
Transition period
- median transition period
- 43 days
- within 30 days
- 16 patients (24%)
- within 14 days
- 5 [8%]
- between 31 and 45 days
- 20 (30%)
- between 46 and 60 days
- 16 (24%)
- between 61 and 90 days
- 14 (21%)
Safety
Dose reduction · no difference
P = 0.319
Discontinuation · no difference
P = 1
- Dose reduction — overall dose reduction
- 24.2%
- Discontinuation — overall discontinuation
- 10.6%
Torsades de pointes (TdP)
- One TdP episode (339 days after dofetilide initiation, 419 days postamiodarone), associated with intercurrent illness and additional QT-prolonging medication exposure
- One
- No TdP during inpatient dofetilide initiation/loading
Original publication
Safety of Dofetilide Initiation Following a Shortened Amiodarone Washout Period. JACC Clin Electrophysiol. Published 29 July 2026. doi:10.1016/j.jacep.2026.06.039
Summarised from the published abstract; every number is checked against it