Clinical significance of device-related complications in clinical trials and implications for future trials: insights from the Antiarrhytmics Versus Implantable Defibrillators (AVID) trial.

Background: Implantation of transvenous implantable cardioverter-defibrillators (ICDs) utilizing a non-thoracotomy approach has become routine therapy for survivors of life-threatening tachyarrhythmias. In the Antiarrhythmics versus Implantable Defibrillator (AVID) Trial, we sought to identify and prospectively characterize the frequency of lead and ICD-related complications. Between June 1, 1993, and April 7, 1997, 539 patients received non-thoracotomy ICDs. A total of 62 first complications occurred. The subclavian route of insertion resulted in more complications than the cephalic vein route, 46 of 339 (14%) versus 6 of 135 (4%), p =.005 as did the abdominal versus pectoral generator site; 31 of 238 (13%) versus 17 of 291 (6%), p <.02. Most dislodgements and system infections tended to occur in the 3 months following implantation, whereas lead fractures continued to occur throughout follow-up. Failure to use peri-operative antibiotics was a predictor of system infection (p =.001). These data suggest that cephalic vein access and pectoral generator site may result in fewer complications. Although implantation techniques and generator technology continue to evolve, the continued occurrence of lead fractures and the need for premature system revision supports the practice of close routine ICD system surveillance.