Aims: The aim of the study was to examine the results of implanting small sized cardioverter defibrillators in the pectoral as opposed to the abdominal area. Hitherto. owing to the large size of the early defibrillators, the site of implantation had been confined to the abdomen.
Methods: Between 30 March 1993 and 1 November 1994, 778 patients from 63 centres in 14 countries underwent their first device implantation. The study was set up to evaluate the safety and the efficacy of Medtronic models 7219 D, a multi-lead abdominal/pectoral implantable cardioverter defibrillator, and 7219 C, a pectoral single-lead Active Can implantable cardioverter defibrillator. There were 155 abdominal and 623 pectoral implants. Survival data were comparable during a mean follow-up period of 4.0 +/- 4.6 months, with no difference regarding the pectoral placement of single (n = 392) or multi-lead (n = 231) devices. The only significant difference was related to severe lead-related events: 5.3% in the pectoral vs 11.6% the abdominal group (P < 0.05). These events were mainly related to lead dislodgement. Kaplan-Meier estimates showed that both single and multi-lead systems, in either the pectoral or abdominal position, demonstrated a similar severe adverse event-free survival.
Conclusion: These findings suggest that an implantable cardioverter defibrillator (18 mm thick, 80 cc volume, 129 g weight) can be implanted in the pectoral position without an increase in clinically relevant adverse events compared to abdominal implantation. Pectoral implantation was associated with significantly reduced lead-related severe adverse event rate.