Atrial fibrillation: chronic: disopyramide maintained sinus rhythm for at least 6 months post-cardioversion.

Clinical bottom line (level 1b)

  1. Patients with recent-onset atrial fibrillation, who took disopyramide compared with placebo following cardioversion back into sinus rhythm were more likely to stay in sinus rhythm (NNT = 4 at 12 months) .
  2. Patients on disopyramide complained of more adverse effects (NNH = 2 at 12 months) , though there was no clear difference in the number of patients who withdrew.
  3. There was no clear effect on mortality.
Karlson et al: European Heart Journal 1988; 9: 284-290
Expires November 2003

The study

Double-blinded concealed randomised trial without intention-to-treat
Setting: four acute hospitals, Sweden

98 patients (aged range 31 to 72 years; mean 60, 74% male) well-defined atrial fibrillation for at least 6 weeks (including patients who had had previous cardioversion or patients relapsing after pharmacological cardioversion)

Excluded if
  • paroxysmal AF
  • AF more than 12 months
  • relative heart volume of more than 700mls/square metre of body surface area
  • previously known 1st degree heart block with bifascicular bundle block or 2nd / 3rd block
  • previous history of intolerance to disopyramide
  • anti-arrhythmic treatment (other than digitalis)
  • possibility of anticholinergic adverse reactions (e.g. glaucoma, prostatic urinary retention
  • MI in previous 6 months
  • impaired renal function (creatinine >125 mmol)
  • inability to co-operate with long-term study


    • Note:
  • All patients were treated with digitalis and anticoagulated, followed by synchronised DC cardioversion using light anaesthesia and energy up to 360J


    • Control Group: (n = , 46 analysed): disopyramide 250 mg bd for 3 days before cardioversion, then placebo
    Experimental Group: (n = , 44 analysed): disopyramide 250 mg bd

    100% followed for 12 months

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    no sinus rhythm 12 months 32
    (69.6%)    		 20
    (45.5%)    		 35%
    (5% to 55%)    		 24.1%
    (4.28% to 43.9%)    		 4
    (2 to 23)
    adverse effects 12 months 8
    (17.4%)    		 28
    (63.6%)    		 -266%
    (-614% to -88%)    		 -46.3%
    (-64.2% to -28.3%)    		 -2
    (-4 to -2)
    withdrawal 12 months 2
    (4.35%)    		 5
    (11.4%)    		 -161%
    (-1178% to 47%)    		 -7.02%
    (-18.1% to 4.06%)    		 -14
    (NNT = 6 to infinity;
    NNH = 25 to infinity)
    death 12 months 0
    (0.00%)    		 2
    (4.55%)    		 %
    (% to %)    		 -4.55%
    (-10.7% to 1.61%)    		 -22
    (NNT = 9 to infinity;
    NNH = 62 to infinity)

  • Common side effects included dry mouth (21/44) micturition disturbances (10/44) and blurred vision (6/44).
  • Six patients could not be cardioverted into sinus rhythm.

    • Comments

    1. The study is too small to show any clear effects on mortality.

    Citation

    1. Karlson BW, Torstensson I, Abjorn C, et al: Disopyramide in the maintenance of sinus rhythm after electrocardioversion of atrial fibrillation. A placebo-controlled one-year follow-up study. European Heart Journal 1988; 9: 284-290
    Contributor: Nick Shenker and Chris Ball, November 2000
    Reviewer:

    Clinical Question.
    Patient chronic AF
    Intervention or Exposure disopyramide
    Comparison placebo
    Outcome cardioversion, side effects, death