Atrial fibrillation: acute: flecainide was better than amiodarone or propafenone for cardioversion

Clinical bottom line (level 1b)

  1. Patients with acute atrial fibrillation who received flecainide compared with propafenone were more likely to revert to sinus rhythm (NNT = 6 at 24 hours) .
  2. Patients who received flecainide compared with amiodarone were more likely to revert to sinus rhythm (NNT = 4 at 24 hours) .
  3. There was no clear difference between amiodarone or propafenone in rates of cardioversion, though propafenone was faster (by roughly 4.5 hours).
Martinez-Marcos et al: American Journal of Cardiology 2000; 86 : 950-953
Expires November 2003

The study

Double-blinded concealed randomised trial with intention-to-treat
Setting: acute hospital, Spain

150 patients (aged mean 60, 53% female) with acute symptomatic atrial fibrillation (lasting 48 hours or less)

Excluded if
  • aged < 18 years
  • pregnancy or lactation
  • duration of AF uncertain or > 48 hours
  • evidence of congestive heart failure or LV ejection fraction < 35%
  • systolic bp < 100 mmHg; ventricular rate < 100 beats/min
  • unstable angina or myocardial infarction within previous month
  • known sick-sinus syndrome or high AV block
  • overt thyroid disease
  • antiarrhythmic therpay within previous 3 months
  • pulmonary fibrosis, renal or hepatic dysfuncion

    Control Group: (n = 50, 50 analysed): propafenone 2 mg/kg over 20 minutes; with a second bolus if no cardioversion after 8 hours
    Experimental Group: (n = 50, 50 analysed): flecainide 2mg/kg over 20 minutes; with a second bolus after 8 hours if no cardioversion
    Experimental Group: (n = 50, 50 analysed): amiodarone 5 mg/kg iv bolus, followed by a continuous infusion of 50 mg/hour

    100% followed for 12 hours
    Outcome notes:
    • adverse effects : arrhythmia, hypotension, rash

    The evidence

    flecainide v. propafenone
    Outcome Time to outcome CER EER RRR
    (95% CI)    		 ARR
    (95% CI)    		 NNT
    (95% CI)
    conversion to sinus rhythm 12 hours 36
    (72.0%)    		 45
    (90.0%)    		 25%
    (3% to 53%)    		 18.0%
    (3.03% to 33.0%)    		 6
    (3 to 33)
    adverse effects 12 hours 7
    (14.0%)    		 6
    (12.0%)    		 14%
    (-140% to 69%)    		 2.00%
    (-11.2% to 15.2%)    		 50
    (NNT = 7 to infinity;
    NNH = 9 to infinity)

    flecainide v. amiodarone
    Outcome Time to outcome CER EER RRR
    (95% CI)    		 ARR
    (95% CI)    		 NNT
    (95% CI)
    conversion to sinus rhythm 12 hours 32
    (64.0%)    		 45
    (90.0%)    		 41%
    (12% to 77%)    		 26.0%
    (10.3% to 41.7%)    		 4
    (2 to 10)
    adverse effects 12 hours 3
    (6.00%)    		 6
    (12.0%)    		 -100%
    (-660% to 47%)    		 -6.00%
    (-17.2% to 5.16%)    		 -17
    (NNT = 19 to infinity;
    NNH = 6 to infinity)

  • There was no clear difference in conversion rates or adverse effects between the groups on amiodarone and propafenone.

    Comments

    1. The study was too small to show any difference in adverse effects between the two groups.
    2. Median time to cardioversion:
      • flecainide: 25 min
      • propafenone: 30 min
      • amiodarone: 333 min

    Citation

    1. Martinez-Marcos FJ, Garcia-Garmendia JL, Ortega-Carpio A, et al: comparison of intravenous flecainide, propafenone, and amiodarone for conversion of acute atrial fibrillation to sinus rhythm. American Journal of Cardiology 2000; 86 : 950-953
    Search Terms:
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient acute atrial fibrillation
    Intervention or Exposure flecainide, propafenone, amiodarone
    Outcome cardioversion to sinus rhythm, adverse effects