Atrial fibrillation: acute: amiodarone was more effective than digoxin at cardioversion.

Clinical bottom line (level 1b)

  1. Patients with recent-onset atrial fibrillation or flutter who received amiodarone compared with digoxin were more likely to revert to sinus rhythm (NNT = 5 at 24 hours) .
  2. There was no clear difference in the number of adverse effects.
Hou et al: European Heart Journal 1995; 16: 521-528
Expires November 2004

The study

Unblinded ?concealed randomised trial with intention-to-treat
Setting: acute hospital, Taiwan

50 patients (aged range 50 to 82 years; mean 70, 86% male) recent-onset atrial fibrillation or flutter (lasting < 10 days and confirmed on ECG or by abrupt-onset symptoms)

Excluded if
  • cardiogenic shock or hypotension
  • WPW syndrome with AF or flutter and RR intervals < 270 ms; sick sinus syndrome
  • paroxysmal AF or flutter previously lasting < 24 hours
  • consumption of any antiarrhythmic drug
  • serum K < 3.5 mmol/l
  • severe hypoxia, metabolic acidosis or thyrotoxicosis
  • AF following surgery


    • Control Group: (n = 24, 24 analysed): digoxin iv 0.013 mg/kg in three divided doses each over 30 minutes 2 hours apart.
    Experimental Group: (n = 26, 26 analysed): amiodarone iv 5 mg/min over 1 hour then 3mg/min for 3 hours, then 1 mg/min for 6 hours, then 0.5 mg/min for 14 hours. Patients then started amiodarone 400 mg po for 7 days then 200 mg daily.

    100% followed for 24 hours

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    no conversion to sinus rhythm 24 hours 7
    (29.2%)    		 2
    (7.69%)    		 74%
    (-15% to 94%)    		 21.5%
    (0.60% to 42.4%)    		 5
    (2 to 170)
    adverse effects 24 hours 0
    (0.00%)    		 2
    (7.69%)    		 %
    (% to %)    		 -7.69%
    (-17.9% to 2.55%)    		 -13
    (NNT = 39 to infinity;
    NNH = 6 to infinity)

  • Adverse effects: amiodarone: 1 patient died; another had worsening heart failure.

    • Comments

    1. Several studies have failed to show that digoxin has any effect on conversion to sinus rhythm in AF.

    Citation

    1. Hou ZY, Chang MS, Chen CY, et al: Acute treatment of recent-onset atrial fibrillation and flutter with a tailored dosing regimen of intravenous amiodarone: a randomized, digoxin-controlled study. European Heart Journal 1995; 16: 521-528
    Search Terms:
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient AF or flutter
    Intervention or Exposure amiodarone
    Comparison digoxin
    Outcome sinus rhythm