Use of dofetilide in adult patients with atrial arrhythmias and congenital heart disease: A PACES collaborative study

Background Arrhythmia management has become the major treatment challenge in adult patients with congenital heart disease (ACHD). Objective We sought to investigate the utility and safety profile of dofetilide for atrial arrhythmias in ACHD. Methods A retrospective chart review was performed. We included patients (age ≥18 years) with congenital heart disease who had atrial fibrillation (AF) or intra-atrial reentrant tachycardia treated with dofetilide. Results We identified 64 patients with a mean age at initiation of 42 ± 14 years. ACHD type included single ventricle (n = 19, 30%), transposition of the great arteries (n = 14, 22%), atrial septal defect (n = 9, 14%), tetralogy of Fallot (n = 8, 12%), atrioventricular canal defect (n = 5, 8%), mitral/aortic stenosis (n = 7, 11%), and other (n = 2, 3%). Thirty-five (55%) had atrial fibrillation, and 29 (45%) had intra-atrial reentrant tachycardia. A total of 3 (4.7%) patients had major inpatient adverse events: torsades de pointes (n = 1, 1.5%), ventricular tachycardia (n = 1, 1.5%), and corrected QT prolongation requiring discontinuation (n = 1, 1.5%). Dofetilide was discontinued in 1 patient because of sinus node dysfunction, and another patient discontinued therapy before discharge because of persistent arrhythmia. Of the patients who were discharged on dofetilide (n = 59, 92%), 40 (68%) had adequate rhythm control and 19 (32%) had partial rhythm control. After a median follow-up of 3 years, 29 (49%) patients remained on dofetilide and 2 (3%) patients died. Reasons for discontinuation included waning effect (n = 16, 57%), side effects (n = 5, 18%), noncompliance (n = 2, 7%), successful ablation (n = 3, 11%), high cost (n = 1, 3.5%), and unknown (n = 1, 3.5%). Conclusion Dofetilide remains a viable antiarrhythmic drug option in this challenging population. At 3 years, 49% remained on dofetilide. Close monitoring of renal function, concomitant medications, and corrected QT interval is required.