November 1, 1998Open Access
View Full PaperConversion of Recent‐Onset Atrial Fibrillation to Sinus Rhythm: Effects of Different Drug Protocols
Key Result
Propafenone and flecainide achieved approximately 75% conversion to sinus rhythm at 8 hours, compared to 57% with intravenous amiodarone and 37% with placebo.
Key Points
- The research aims to evaluate the efficacy and safety of different drug regimens for converting recent-onset atrial fibrillation to sinus rhythm.
- Randomized trial involving 417 hospitalized patients in NYHA Class ≤ 2, free of heart failure.
- Patients received various treatments: placebo, i.v. amiodarone, i.v. propafenone, oral propafenone, or oral flecainide.
- Holter ECG monitoring assessed conversions to sinus rhythm at 1, 3, and 8 hours.
- i.v. propafenone showed higher conversion rates within 1 hour compared to oral regimens; approximately 75% at 8 hours.
- i.v. amiodarone conversion was not different from placebo until 8 hours (57% conversions).
- Conversion was observed in 37% of placebo-treated patients at 8 hours.
Study Design
Type
RCT (n=417)
Structured PICO
Do different antiarrhythmic drug protocols (amiodarone, propafenone, flecainide) improve conversion to sinus rhythm compared to placebo in hospitalized patients with recent-onset atrial fibrillation?
P
Population
417 hospitalized patients with recent-onset atrial fibrillation (≤ 7 days duration), NYHA Class ≤ 2, and free of heart failure, monitored for 8 hours.
I
Intervention
i.v. amiodarone (5 mg/kg bolus, followed by 1.8 g/24 hours), i.v. propafenone (2 mg/kg bolus, followed by 0.0078 mg/kg/min), p.o. propafenone (600 mg single dose), or p.o. flecainide (300 mg single dose)
C
Comparator
Placebo
O
Outcome
Conversion to sinus rhythm measured at 1, 3, and 8 hourssurrogate
Single-dose oral loading with propafenone or flecainide are effective alternatives to conventional intravenous regimens for converting recent-onset atrial fibrillation to sinus rhythm.
Main Result
Absolute Event Rate: 75% vs 37%
Abstract
UNLABELLED: In a population of 417 hospitalized patients, the efficacy and safety of different drug regimens administered to convert atrial fibrillation (AF) of recent onset (< or = 7 days duration) to sinus rhythm were evaluated. All patients were in NYHA Class < or = 2, and free of heart failure. They were randomly allocated to treatment with placebo in 121 patients; i.v. amiodarone, 5 mg/kg bolus, followed by 1.8 g/24 hours in 51 patients; i.v. propafenone, 2 mg/kg bolus, followed by 0.0078 mg/kg/min in 57 patients; p.o. propafenone, 600 mg p.o. in a single dose in 119 patients; and p.o. flecainide, 300 mg p.o. in a single dose in 69 patients. All patients were continuously monitored by Holter ECG, and the number of conversions to sinus rhythm was measured at 1, 3, and 8 hours. RESULTS: (1) I.v. propafenone resulted in a higher conversion rate within 1 hour compared with the oral loading regimens of propafenone or flecainide, but the conversion rates at 3 and 8 hours were comparable, approximately 75% at 8 hours; 2) i.v. amiodarone was not different from placebo until 8 hours when it was associated with 57% of conversions; (3) conversion to sinus rhythm at 8 hours was observed in 37% of the placebo treated patients. Serious adverse effects occurred in few patients: two patients treated with flecainide and one treated with i.v. propafenone experienced left ventricular decompensation; one patient treated with placebo and two treated with flecainide had atrial flutter with rapid ventricular response. In conclusion, single-dose, oral loading with propafenone or flecainide are acceptable alternatives to conventional drug regimens in selected hospitalized patients. In addition, the measure of a placebo effect is mandatory in studies of recent-onset AF.