The safety of flecainide treatment of atrial fibrillation: long‐term incidence of sudden cardiac death and proarrhythmic events

Abstract.  Almroth H, Andersson T, Fengsrud E, Friberg L, Linde P, Rosenqvist M, Englund A (Orebro University Hospital, Orebro; Danderyd Hospital and Karolinska Institutet at Danderyd Hospital, Stockholm; and Karolinska Institutet at Stockholm South Hospital, Sweden). The safety of flecainide treatment of atrial fibrillation: long-term incidence of sudden cardiac death and proarrhythmic events. J Intern Med 2011; 270: 281–290. Objective.  To assess the safety of long-term treatment with flecainide in patients with atrial fibrillation (AF), particularly with regard to sudden cardiac death (SCD) and proarrhythmic events. Design.  Retrospective, observational cohort study. Setting.  Single-centre study at Orebro University Hospital, Sweden. Subjects.  A total of 112 patients with paroxysmal (51%) or persistent (49%) AF (mean age 60 ± 11 years) were included after identifying all patients with AF who initiated oral flecainide treatment (mean dose 203 ± 43 mg per day) between 1998 and 2006. Standard exclusion/inclusion criteria for flecainide were used, and flecainide treatment was usually combined with an atrioventricular-blocking agent (89%). Main outcome measure.  Death was classified as sudden or nonsudden according to standard definitions. Proarrhythmia was defined as cardiac syncope or life-threatening arrhythmia. Results.  Eight deaths were reported during a mean follow-up of 3.4 ± 2.4 years. Compared to the general population, the standardized mortality ratios were 1.57 (95% confidence interval (CI) 0.68–3.09) for all-cause mortality and 4.16 (95% CI 1.53–9.06) for death from cardiovascular disease. Three deaths were classified as SCDs. Proarrhythmic events occurred in six patients (two each with wide QRS tachycardia, 1 : 1 conducted atrial flutter and syncope during exercise). Conclusion.  We found an increased incidence of SCD or proarrhythmic events in this real-world study of flecainide used for the treatment of AF. The findings suggest that further investigation into the safety of flecainide for the treatment of patients with AF is warranted.