Cardiac Arrest: post-arrest: implantable defibrillators reduced mortality.

Clinical bottom line (level 1b)

  1. Patients following a VF or VT cardiac arrest from a myocardial infarction who received an implantable defibrillator compared with conventional therapy, were more likely to be alive after 2 years (NNT = 5 at 24 months) .
  2. Implantable defibrillation had no clear effect on prolonged syncope or cardiac transplantation.
Wever et al: Circulation 1995; 91: 2195-2203
Expires October 2003

The study

Unblinded ?concealed randomised trial ?with intention-to-treat
Setting: 3 university hospitals, The Netherlands

60 patients (aged mean 58, 90% male) with at least one successful resuscitation from cardia arrest (VT or VF) following a myocardial infarction.

Excluded if
  • >75 years old
  • no previous resuscitations from cardiac arrest
  • interval between index arrhythmia and previous infarction <4 weeks
  • interval from index episode to entry in study >3 months
  • no inducibility of ventricular tachyarrhythmia by electrical stimulation
  • not tolerant to any oral antiarrhythmic drug regimen
  • frequent episodes requiring defibrillation during baseline observation
  • established indication for surgical treatment or percutaneous transluminal coronary angiography
  • unipolar pacing device
  • life expectancy <1 year (from terminal heart disease or malignancy)
  • other severe disease requiring hospitalisation


    • Note:
  • Patients were stratified before randomisation on the basis of the number or akinetic segments on cineangiography.


    • Control Group: (n = 31, 31 analysed): conventional therapy: using class Ia, IC or III drugs, followed by surgical ablation if fit for surgery, otherwise insertion of a defibrillator.
    Experimental Group: (n = 29, 29 analysed): implantable cardioverter-defibrillator

    100% followed for 24 months range 3 days to 56 months
    Outcome notes:
    • primary outcome : death, cardiac transplantation, prolonged syncope

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    primary outcome weeks 13
    (41.9%)    		 4
    (13.8%)    		 67%
    (11% to 88%)    		 28.1%
    (6.71% to 49.6%)    		 4
    (2 to 15)
    total mortality 24 months 11
    (35.5%)    		 4
    (13.8%)    		 61%
    (-8% to 86%)    		 21.7%
    (0.69% to 42.7%)    		 5
    (2 to 150)

    Comments

    1. Late implantable cardioverter-defibrillator implantation was not excluded from conventional therapy
    2. Combination of implantable cardioverter-defibrillator therapy with antiarrhythmic drug treatment was considered in patients with a high recurrence rate of ventricular tachyarrhythmia episodes requiring defibrillation.

    Citation

    1. Wever EF, Hauer RN, van Capelle F, et al: Randomized Study of Implantable Defibrillator as First-Choice Therapy Versus Conventional Strategy in Postinfarct Sudden Death Survivors. Circulation 1995; 91: 2195-2203
    Contributor: Clare Wotton and Chris Ball, October 1999
    Reviewer: -

    Clinical Question.
    Patient cardiac arrest
    Intervention or Exposure implantable defibrillator
    Comparison conventional therapy: antiarrhythmics
    Outcome mortality