Atrial fibrillation: paroxysmal: fewer patients stopped flecainide than quinidine.

Clinical bottom line (level 1b)

  1. Patients with symptomatic paroxysmal atrial fibrillation who took flecainide rather than quinidine were more likely to be still on medication (NNT = 8 at 12 months) .
  2. This difference was due to adverse effects - there was no clear difference in effectiveness.
Naccarelli et al: American Journal of Cardiology 1996; 77: 53A-59A
Expires February 2004

The study

Unblinded ?concealed randomised trial without intention-to-treat
Setting: 53 acute hospitals, North America, Europe

239 patients (aged mean 57 years, 52% male) symptomatic paroxysmal atrial fibrillation and/or atrial flutter

Excluded if
  • <18 years old
  • on anti-arrhythmics (except beta-blockers and digoxin) within 4 weeks
  • previous or current unstable angina or MI
  • severe heart failure
  • myasthenia gravis
  • cardiogenic shock
  • conduction delay, anterior fascicle block
  • cardiac surgery within two months
  • need to continue other antiarrhythmics
  • digitalis toxicity
  • any other clinically significant disease


    • Control Group: (n = 117, 117 analysed): quinidine 250 mg to 324 mg bd to tds increased to 1000 to 2000 mg
    Experimental Group: (n = 122, 122 analysed): flecainide 50 mg bd po increased by 50 mg every 4 days to a maximum of 150 to 300 mg

    100% followed for 12 months

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    discontinued therapy 12 months 64
    (54.7%)    		 51
    (41.8%)    		 24%
    (0% to 41%)    		 12.9%
    (0.33% to 25.5%)    		 8
    (4 to 300)
    discontinued therapy due to adverse effects 12 months 35
    (29.9%)    		 22
    (18.0%)    		 40%
    (4% to 62%)    		 11.9%
    (1.14% to 22.6%)    		 8
    (4 to 88)
    discontinued therapy due to inadequate response 12 months 14
    (12.0%)    		 12
    (9.84%)    		 18%
    (-70% to 60%)    		 2.13%
    (-5.78% to 10.0%)    		 47
    (NNT = 10 to infinity;
    NNH = 17 to infinity)

    Citation

    1. Naccarelli GV, Dorian P, Hohnloser SH, et al: Prospective comparison of flecainide versus quinidine for the treatment of paroxysmal atrial fibrillation/ flutter. American Journal of Cardiology 1996; 77: 53A-59A
    Search Terms: atrial fibril* in Cochrane
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient AF
    Intervention or Exposure flecainide
    Comparison quinidine
    Outcome discontinued therapy