Atrial fibrillation: chronic: few remained in sinus rhythm long-term following DC cardioversion .

Clinical bottom line (level 1b)

  1. Only a quarter of patients with atrial fibrillation who had serial cardioversion were in sinus rhythm after 4 years.
  2. Only 10% of patients who had one cardioversion were in sinus rhythm after 4 years.
  3. Patients were more likely to revert back to AF if:
    • AF has been present for longer than 3 months
    • severe heart failure
Van Gelder et al: Archives of Internal Medicine 1996; 156: 2585-2592
Expires November 2003

The study

Prospective cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: two acute hospitals, Holland

236 patients (aged mean 63 years, 56% male) chronic atrial fibrillation (> 24 hours: confirmed on 2 ECGs and 24 hour Holter monitoring)

Excluded if
  • NYHA class IV heart failure
  • unstable angina
  • acute myocardial infarction in last 4 weeks
  • relapsed into AF whilst on antiarrhythmic medication



    • Factors studied:
  • sinus rhythm, thromboembolic event, haemorrhagic complication, congestive heart failure, antiarrhythmic drug adverse effect
  • duration of AF: 3 to 35 months
  • 36 months or more
  • NYHA class III
  • aged > 56


    • All patients had elective DC cardioversion, following 4 weeks of anticoagulation (INR 2.4 to 4.8). Anticoagulation was stopped one month after restoration. Patients received no antiarrhythmic medication. If patients relapsed, cardioversion was repeated. Successive recurrences led to the use of sotalol, flecainide and amiodarone in order. Patients who relapsed a year after cardioversion did not change their medication.

    Cox proportional regression analysis performed on prognostic factors.

    100% followed for mean of 3.7 years (range 0.2 to 7.0 years)
    Outcomes studied:
  • sinus rhythm following serial cardioversion at 1 year
  • sinus rhythm following serial cardioversion at 4 years
  • sinus rhythm following one cardioversion at 4 years
  • thromboembolic event at 4 years
  • haemorrhagic complication at 4 years
  • congestive heart failure at 4 years
  • antiarrhythmic drug adverse effect at 4 years
  • failure of serial cardioversion

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    sinus rhythm following serial cardioversion at 1 year mean of 3.7 years (range 0.2 to 7.0 years) / 42%
    (% to %)
    sinus rhythm following serial cardioversion at 4 years mean of 3.7 years (range 0.2 to 7.0 years) / 27%
    (% to %)
    sinus rhythm following one cardioversion at 4 years mean of 3.7 years (range 0.2 to 7.0 years) 24/236 10%
    (6.3% to 14%)
    thromboembolic event at 4 years mean of 3.7 years (range 0.2 to 7.0 years) 2/236 0.8%
    (0.0% to 2.0%)
    haemorrhagic complication at 4 years mean of 3.7 years (range 0.2 to 7.0 years) 13/236 5.5%
    (2.6% to 8.4%)
    congestive heart failure at 4 years mean of 3.7 years (range 0.2 to 7.0 years) 44/236 19%
    (14% to 24%)
    antiarrhythmic drug adverse effect at 4 years mean of 3.7 years (range 0.2 to 7.0 years) 11/236 4.7%
    (2.0% to 7.4%)
    failure of serial cardioversion mean of 3.7 years (range 0.2 to 7.0 years) 93/236 39%
    (33% to 46%)

    prognostic factor for
    failure of serial cardioversion     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    duration of AF: 3 to 35 months ? /
    (21%)     		2.1
    (1.3 to 3.4)     		7
    (4 to 21)
    36 months or more ? /
    (3.0%)     		5.0
    (3.0 to 8.3)     		10
    (6 to 18)
    NYHA class III ? /
    (27%)     		1.8
    (1.3 to 2.6)     		8
    (5 to 18)
    aged > 56 ? /
    (18%)     		1.5
    (1.0 to 2.2)     		15
    (7 to infinity)

    • Around half of patients who remained in sinus rhythm required two or fewer cardioversions and no prophylactic drug therapy.

    Citation

    1. Van Gelder IC, Crijns HJ, Tieleman RG, et al: Chronic atrial fibrillation: success of serial cardioversion therapy and safety of oral anticoagulation. Archives of Internal Medicine 1996; 156: 2585-2592
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient chronic AF
    Intervention or Exposure risk factors
    Outcome reversion back to AF