A PROSPECTIVE, RANDOMIZED EVALUATION OF A NONTHORACOTOMY IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR LEAD SYSTEM

BAKER, J.H., II, ET AL.: A Prospective, Randomized Evaluation of a Non thoracotomy Implantable Cardioverter Defibrillator Lead System. Nontho racotomy lead systems for ICDs have been developed that obviate the ne ed for a thoracotomy and reduce the morbidity and mortality associated with implantation. However, an adequate DFT cannot be achieved in som e patients using transvenous electrodes alone. Thus, a new subcutaneou s ''array'' electrode was designed and tested in a prospective, random ized trial that compared the DFT obtained using monophasic shock wavef orms with a single transvenous lead alone that has two defibrillating electrodes, the transvenous lead linked to a subcutaneous/submuscular patch electrode, and the transvenous lead linked to the investigationa l array electrode. There were 267 patients randomized to one of the th ree nonthoracotomy ICD lead systems. All had DFTs that met the implant ation criterion of less than or equal to 25 J. The resultant study pop ulation was 82% male and 18% female, mean age of 63 +/- 11 years. The indication for ICD implantation was monomorphic VT in 70%, VF in 19%, monomorphic VT/VF in 6%, and polymorphic VT in 4% of the patients, res pectively The mean LVEF was 0.33 +/- 0.13, The mean DFT obtained with tile transvenous lead alone was 17.5 +/- 4.9 J as compared to 16.5 +/- 5.5 J with the lead linked to a patch electrode (P = NS), and 14.9 +/ - 5.6 with the lead linked to the array electrode (array versus lead a lone, P = 0.0001; army versus lead/patch, P = 0.007). The results of t his investigation suggest that tile subcutaneous array may be superior to the standard patch as a subcutaneous electrode to lower the DFT an d increase the margin of safety for successful nonthoracotomy defibril lation.