Atrial fibrillation: amiodarone prevents recurrence than sotalol or propafenone

Clinical bottom line (level 1b)

  1. Patients with at least one episode of atrial fibrillation who receive amiodarone compared with sotalol or propafenone are less likely to revert to AF (NN T = 4 at 16 years) .
  2. Patients on amiodarone compared with sotalol or propafenone are less likely to stop their medication (NN T = 8 at 16 months) .
  3. There is no clear effect on mortality.
Roy et al: New England Journal of Medicine 2000; 342 : 913-920
Expires April 2004

The study

Unblinded ?concealed randomised trial with intention-to-treat
Setting: 19 acute hospitals, Canada

403 patients (aged mean 65, 55% male) with at least one episode of symptomatic atrial fibrillation (confirmed on ECG) within the previous 6 months for which long-term aniarrhythmic therapy was planned

Excluded if
  • aged < 18
  • premenopausal women who had not undergone tubal ligation or hysterectomy
  • medical condition making survival > 1 year unlikely
  • need for antiarrhythmic therapy for arrhythmias other than AF
  • previous long-term therapy of study drugs (lasting 4 weeks or more) or intolerance of study drugs
  • untreated hypothyroidism
  • corrected QT interval > 480 msec or an uncorrected QT interval > 500 msec in the absence of bundle branch block
  • bradycardia (< 50 beats/min), second or third degree heart block, or sinus pauses > 2 seconds without a permanent pacemaker
  • moderate or severe cardiac failure (NYHA class III or IV)
  • atrial fibrillation associated with an acute reversible condition
  • serum creatinine > 250 micromol/l
  • serum ALT > 2.5 upper limit of normal
  • chronic lung disease requiring bronchodilator therapy
  • Wolff-Parkinson-White syndrome
  • longest episode of AF lasted < 10 minutes
  • AF known to be continuous for more than 6 months
  • myocardial infarction during previous 6 months

    Note:
  • All patients with AF for > 48 hours were anticoagulated (adjusted so INR > 2.0 for at least 3 weeks before randomisation)

    Control Group: (n = 202, 202 analysed): sotalol 80 mg or 160 mg every 12 hours; or propafenone 150 mg or 300 mg every 12 hours. Lower doses were used for patients with renal dysfunction, or aged > 70. If the first drug was unsuccessful, the second could be used.
    Experimental Group: (n = 201, 201 analysed): amiodarone 10 mg/kg per day for 15 ays, then 300 mg per day for 3 weeks, then 200 mg per day
    Patients who failed to revert to sinus rhythm on medication were cardioverted after 14 days on amiodarone and after 4 weeks on sotalol or propafenone.
    100% followed for 16 months
    Outcome notes:
    • recurrence of AF :

    The evidence

    Outcome Time to outcome CER EER RRR
    (95% CI)    		 ARR
    (95% CI)    		 NN T
    (95% CI)
    recurrence of AF 16 months 127
    (62.9%)    		 71
    (35.3%)    		 44%
    (30% to 55%)    		 27.6%
    (18.2% to 36.9%)    		 4
    (3 to 6)
    stopped study medication 16 months 93
    (46.0%)    		 68
    (33.8%)    		 27%
    (6% to 42%)    		 12.2%
    (2.72% to 21.7%)    		 8
    (5 to 37)
    death 16 months 8
    (3.96%)    		 9
    (4.48%)    		 -13%
    (-190% to 55%)    		 -0.52%
    (-4.44% to 3.41%)    		 -190
    (NNT = 29 to infinity;
    NNH = 23 to infinity)

    Comments

    1. 4 patients stopped amiodarone due to pulmonary abnormalities and 3 due to thyroid disease.

    Citation

    1. Roy D, Talajic M, Dorian P, et al: amiodarone to prevent recurrence of atrial fibrillation. New England Journal of Medicine 2000; 342 : 913-920
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    Contributor: Chris Ball, April 2000
    Reviewer:

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