Atrial fibrillation: acute: ibutilide was more effective and safer than procainamide for cardioversion.

Clinical bottom line (level 1b)

  1. Patients with recent-onset atrial fibrillation or flutter who received ibutilide compared with procainamide were more likely to cardiovert (NNT = 3 at 24 hours) .
  2. Patients had fewer side-effects (NNT = 5 at 72 hours) , though there was no clear difference in the number that needed to withdraw.
Volgman et al: Journal of the American College of Cardiology 1998; 31 (6): 1414-1419
Expires November 2003

The study

Double-blinded concealed randomised trial without intention-to-treat
Setting: five acute hospitals, USA

127 patients (aged range 22 to 92 years; mean 66, 73% male) atrial fibrillation or flutter for 3 hours to 90 days (mean 21 days)

Excluded if
  • <18 years old
  • weighed < 40 kg, >100 kg
  • child-bearing potential
  • corrected QT interval >440 ms
  • haemodynamically unstable (heart rate < 60, bp < 90/60 mmHg)
  • symptoms of unstable angina or heart failure (NYHA Class III or IV)
  • abnormal electrolytes or LFTs
  • MI within 30 days
  • history of torsade de pointes, 2nd or 3rd degree heart block
  • any serious medical condition affecting study interpretation
  • on study medication within previous 30 days


    • Note:
  • Patients were stratified for type of arrhythmia and its duration before randomisation.Patients with AF for > 3 days were anticoagulated unless tranoesophageal echocardiography showed no atrial clot. Patients were allowed to continue beta-blockers, calcium-channel blockers or digoxin.


    • Control Group: (n = , 60 analysed): procainamide 400 mg iv infusion over 10 minutes repeated twice continued until cardioversion
    Experimental Group: (n = , 60 analysed): ibutilide 10 mg iv infusion over 10 minutes repeated once continued until cardioversion

    94% followed for 72 hours
    Outcome notes:
    • adverse effects : headache, hypotension, hypethesia, flushing, dizziness

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    no conversion to sinus rhythm 24 hours 49
    (81.7%)    		 25
    (41.7%)    		 49%
    (30% to 63%)    		 40.0%
    (24.1% to 55.9%)    		 3
    (2 to 4)
    adverse effects 72 hours 28
    (46.7%)    		 17
    (28.3%)    		 39%
    (1% to 63%)    		 18.3%
    (1.32% to 35.3%)    		 5
    (3 to 76)
    discontinued medication 24 hours 3
    (5.00%)    		 3
    (5.00%)    		 0%
    (-376% to 79%)    		 0.00%
    (-7.80% to 7.80%)    		 infinity
    (NNT = 13 to infinity;
    NNH = 13 to infinity)

  • One patient on ibutilide had a episode of non-sustained VT.

    • Comments

    1. Short follow-up makes these results less certain.

    Citation

    1. Volgman AS, Carberry PA, Stambler B, et al: Conversion efficacy and safety of intravenous ibutilide compared with intravenous procainamide in patients with atrial flutter or fibrillation. Journal of the American College of Cardiology 1998; 31 (6): 1414-1419
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient acute AF
    Intervention or Exposure ibutilide
    Comparison procainamide
    Outcome cardioversion, side effects