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Therapeutics

Propafenone converted recent-onset atrial fibrillation to sinus rhythm in patients with and without heart disease

ACP J Club. 1997 Nov-Dec;127:70. doi:10.7326/ACPJC-1997-127-3-070


Source Citation

Boriani G, Biffi M, Capucci A, et al. Oral propafenone to convert recent-onset atrial fibrillation in patients with and without underlying heart disease. A randomized, controlled trial. Ann Intern Med. 1997 Apr 15; 126:621-5.


Abstract

Objective

To determine the effectiveness and safety of propafenone for converting atrial fibrillation (AF) to sinus rhythm in patients with and without structural heart disease.

Design

Randomized, single-blind, placebo-controlled trial with 8-hour follow-up.

Setting

3 teaching hospitals in Italy.

Patients

240 patients (mean age 59 y, 57% men) who had recent-onset AF (≤ 7 d). Exclusion criteria were age > 80 years; heart failure (> New York Heart Association class II); mean ventricular rate during AF < 70 beats/min; recent myocardial infarction (< 6 mo); unstable angina pectoris; ventricular preexcitation; complete bundle-branch block, bifascicular or second- or third-degree atrioventricular block; sick sinus syndrome; hypokalemia; renal, hepatic, or thyroid dysfunction; severe hypoxia or metabolic disturbances; or recent (< 8 h) or long-term treatment with digoxin or antiarrhythmic drugs. Based on clinical history, physical examination, echocardiography, and chest radiography, patients were classified as having structural heart disease, hypertension without structural heart disease, or neither.

Intervention

Patients were allocated to oral propafenone (two 300-mg tablets, single dose, single-blind) or placebo.

Main outcome measures

Rates of conversion to sinus rhythm (lasting > 1 h) at 3 and 8 hours.

Main results

At 3 and 8 hours, more patients who received propafenone converted to sinus rhythm than those who received placebo (P < 0.001 for both) (Table). Subgroup analysis found that conversion rates were higher in the propa-fenone group than in the placebo group for patients with and without structural heart disease at 3 hours (P < 0.001 and P = 0.02, respectively) and for those with hypertension and structural heart disease at 8 hours (P < 0.001 for both). No proarrhythmic ventricular effects or excess sustained atrial flutter or tachycardia and ventricular pauses occurred with propafenone. QRS widening, hypotension, bradycardia, or junctional rhythm were seen in 9 patients (8%) receiving propafenone.

Conclusion

Single-dose oral propafenone seemed to be safe and was more effective than placebo for converting recent-onset atrial fibrilation to sinus rhythm in patients with and without structural heart disease.

Source of funding: No external funding.

For article reprint: Dr. G. Boriani, Instituto di Cardiologia, Università degli Studi di Bologna, Via Massarenti 9, 40138 Bologna, Italy.


Table. Oral propafenone vs placebo*

Outcome Propafenone EER Placebo CER RBI (95% CI) ABI |EER-CER| NNT (CI)
Conversion at 3 h 45% 18% 150% (65 to 284) 27% 4 ( 3 to 6)
Conversion at 8 h 76% 37% 106% (62 to 167) 39% 3 ( 2 to 4)

*Abbreviations defined in Glossary; RBI, ABI, NNT, and CI calculated from data in article.


Commentary

The study by Boriani and colleagues is the latest in a series on conversion of recent-onset AF to sinus rhythm by using propafenone, flecainide, or amiodarone (1-3). From these small studies, a picture emerges that, at 8 hours, a single oral dose (600 mg) of propafenone seems to be effective in converting about three quarters of patients with recent-onset AF to sinus rhythm compared with just over one third of patients receiving placebo.

Although this study found that one quarter of patients with some form of structural heart disease (generally mild) and one third of patients with hypertension had similar conversion rates, concerns remain about the safety of propafenone because studies of this size do not have adequate statistical power to detect infrequent but important adverse effects. Thus, the results must not be extrapolated to patients with more severe structural heart disease and surveillance for adverse effects must be continued.

Finally, for the many more patients with recurrent AF or those with AF that is not of recent onset, the answer is less clear and awaits the results of ongoing trials on pharmacologic conversion and prevention of recurrent AF.

Koon K. Teo, MD, PhD
University of AlbertaEdmonton, Alberta, Canada


References

1. Capucci A, Lenzi T, Boriani G, et al. Effectiveness of loading oral flecainide for converting recent-onset atrial fibrillation to sinus rhythm in patients without organic heart disease or with only systemic hypertension. Am J Cardiol. 1992;70:69-72.

2. Capucci A, Boriani G, Botto GL, et al. Conversion of recent-onset atrial fibrillation by a single oral loading dose of propafenone or flecainide. Am J Cardiol. 1994;74:503-5.

3. Boriani G, Capucci A, Lenzi T, Sanguinetti M, Magnani B. Propafenone for conversion of recent-onset atrial fibrillation. A controlled comparison between oral loading dose and intravenous administration. Chest. 1995;108:355-8.