Relative effectiveness of the implantable cardioverter-defibrillator and antiarrhythmic drugs in patients with varying degrees of left ventricular dysfunction who have survived malignant ventricular arrhythmias. AVID Investigators. Antiarrhythmics Versus Implantable Defibrillators

J Am Coll Cardiol. 1999 Oct;34(4):1090-5. doi: 10.1016/s0735-1097(99)00327-7.


Objectives: We sought to assess the effect of baseline ejection fraction on survival difference between patients with life-threatening ventricular arrhythmias who were treated with an antiarrhythmic drug (AAD) or implantable cardioverter-defibrillator (ICD).

Background: The Antiarrhythmics Versus Implantable Defibrillators (AVID) study demonstrated improved survival in patients with ventricular fibrillation or ventricular tachycardia with a left ventricular ejection fraction (LVEF) < or =0.40 or hemodynamic compromise.

Methods: Survival differences between AAD-treated and ICD-treated patients entered into the AVID study (patients presenting with sustained ventricular arrhythmia associated with an LVEF < or =0.40 or hemodynamic compromise) were compared at different levels of ejection fraction.

Results: In patients with an LVEF > or =0.35, there was no difference in survival between AAD-treated and ICD-treated patients. A test for interaction was not significant, but had low power to detect an interaction. For patients with an LVEF 0.20 to 0.34, there was a significantly improved survival with ICD as compared with AAD therapy. In the smaller subgroup with an LVEF <0.20, the same magnitude of survival difference was seen as that in the 0.20 to 0.34 LVEF subgroup, but the difference did not reach statistical significance.

Conclusions: These data suggest that patients with relatively well-preserved LVEF (> or =0.35) may not have better survival when treated with the ICD as compared with AADs. At a lower LVEF, the ICD appears to offer improved survival as compared with AADs. Prospective studies with larger patient numbers are needed to assess the effect of relatively well-preserved ejection fraction (> or =0.35) on the relative treatment effect of AADs and the ICDs.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Amiodarone / administration & dosage*
  • Amiodarone / adverse effects
  • Anti-Arrhythmia Agents / administration & dosage*
  • Anti-Arrhythmia Agents / adverse effects
  • Defibrillators, Implantable*
  • Female
  • Hemodynamics / drug effects
  • Hemodynamics / physiology
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Stroke Volume / drug effects
  • Stroke Volume / physiology
  • Survival Rate
  • Tachycardia, Ventricular / mortality
  • Tachycardia, Ventricular / physiopathology
  • Tachycardia, Ventricular / therapy*
  • Treatment Outcome
  • Ventricular Dysfunction, Left / mortality
  • Ventricular Dysfunction, Left / physiopathology
  • Ventricular Dysfunction, Left / therapy*
  • Ventricular Fibrillation / mortality
  • Ventricular Fibrillation / physiopathology
  • Ventricular Fibrillation / therapy*
  • Ventricular Function, Left / drug effects
  • Ventricular Function, Left / physiology


  • Anti-Arrhythmia Agents
  • Amiodarone