Safety of flecainide versus propafenone for the long-term management of symptomatic paroxysmal supraventricular tachyarrhythmias: Report from the Flecainide and Propafenone Italian Study (FAPIS) group

In order to compare the long-term safety of flecainide and propafenone,an open label, randomized, parallel group study was performedin 335 patients with paroxysmal atrial fibrillation (n=200)or paroxysmal supra ventricular tachycardia (n=135), and nohistory of heart disease. Patients were treated with an initialdaily dose of flecainide 100 mg (n=72) or propafenone 450 mg(n=63) for paroxysmal supraventricular tachycardia and flecainide200 mg (n=97) or propafenone 450 mg (n=103) for paroxysmal atrialfibrillation. Dose escalations were permitted after 2 attacks,up to a maximum of flecainide 300 mg or propafenone 900 mg.day^–1. Follow-up duration was 12 months, or when patientsstopped the treatment as a result of inadequate efficacy oradverse experiences. Twelve patients on flecainide reported 16 cardiac adverse experiences,of whom six discontinued the treatment. Seven propafenone patientshad eight cardiac adverse experiences, of whom five discontinuedthe treatment. Serious proarrhythmic events were infrequent:one case of ventricular tachycardia on propafenone; two casesof atrial fibrillation with rapid ventricular response on flecainide,associated in one patient with pulmonary oedema. An intention-to-treat analysis showed that the probability of12 months' safe and effective treatment of paroxysmal supraventriculartachycardia was 93% for flecainide and 86% for propafenone (P=0·24),whereas in paroxysmal atrial fibrillation it was 77% for flecainideand 75% for propafenone (P=0·72). In conclusion, flecainide and propafenone were safe in the long-termtreatment of patients with paroxysmal supraventricular tachyarrhythmiasand without evidence of clinically significant heart disease.