Tachycardia: Implantable defibrillators decreased death.

Clinical bottom line (level 1b)

  1. Patients resuscitated from near-fatal ventricular arrhythmias who were given an implantable defibrillator, were less likely to die than those given antiarrhythmic drug therapy.
The Antiarrhythmics Versus Implantable Defibrillators (AVID) Investigators : New England Journal of Medicine 1997; 337 (22): 1576-1583
Expires October 2004

The study

Unblinded ?concealed randomised trial ?with intention-to-treat
Setting: multicentre, USA

1016 patients (aged mean 65 years, 80% male) resuscitated from near-fatal ventricular fibrillation, sustained ventricular tachycardia with syncope or sustained ventricular tachycardia with an ejection fraction of 0.40 or less and symptoms suggesting severe haemodynamic compromise due to the arrhythmia (near-syncope, congestive heart failure or angina)

Excluded if
  • physician felt unable to randomise; common reasons given included
  • not eligible for treatment with amiodarone
  • history of asthma
  • low left ventricular ejection fraction
  • history of congestive heart failure


    • Note:
  • 87% of patients were White.


    • Control Group: (n = 509, 509 analysed): antiarrhythmic drug therapy-356 patients were assigned to amiodarone (as they were not considered candidates for sotalol due to concern about heart failure, low ejection fraction or both); in the remaining patients, randomisation into amiodarone (79 patients) or sotalol (74) took place.
    Experimental Group: (n = 507, 507 analysed): implantable cardioverter-defibrillator- any advanced state-of-the-art device that met specified criteria
    Defibrillators were manufactured by Guidant/CPI, Sulzer Intermedics, Medtronic and Ventritex.
    99.7% followed for ? mean follow-up 18.2±12.2 months

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    death 18 months 122
    (24.0%)    		 80
    (15.8%)    		 34%
    (15% to 49%)    		 8.19%
    (3.31% to 13.1%)    		 12
    (8 to 30)

    Comments

    1. Approximately 20% of patients had crossed over to or added the other therapy by 24 months. The crossover rate was higher among those initially assigned to therapy with a defibrillator.
    2. In patients treated with amiodarone, one had nonfatal torsade-de-pointes and one died from pulmonary toxicity.

    Citation

    1. The Antiarrhythmics Versus Implantable Defibrillators (AVID) Investigators , : A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. New England Journal of Medicine 1997; 337 (22): 1576-1583
    Contributor: Clare Wotton and Bob Phillips, October 1999
    Reviewer:

    Clinical Question.
    Patient ventricular arrhythmias
    Intervention or Exposure antiarrhythmic drugs
    Comparison implantable defibrillator
    Outcome mortality