Implantable defibrillators show major survival gains

Trials halted based on superiority to drugs

The National Heart, Lung and Blood Institute (NHLBI) of the National Institutes of Health in Rockville, MD, terminated the Antiarrhythmics vs. Implantable Defibrillators (AVID) trial on April 7 on the basis that implantable defibrillators improved overall survival in patients with ventricular fibrillation and serious ventricular tachycardia. Average hospital charges for a defibrillator implantation are $66,600. Average charges for monitoring a hospitalized patient undergoing administration of antiarrhythmic drugs is $34,000. Over time, the defibrillator strategy becomes less costly because fewer days in the hospital are consumed.

The trial had been comparing treatment strategies for about 1,000 patients with life-threatening heart arrhythmias since 1993 at 50 clinical sites. The results of the study should streamline therapeutic approach to these patients.

Patients had been randomly assigned to receive treatment with either a defibrillator or with a drug — either amiodarone or sotalol — to see which strategy reduced mortality more significantly. After one year, patients in the defibrillator group had a 38% reduction in deaths compared to antiarrhythmics group. The number decreased to about 25% during the second and third years, but NHLBI director Claude Lenfant, MD, says that even though the relative benefit declined over time, the difference between the two strategies was still very significant.