abstract
- OBJECTIVES: The long-term efficacy and safety of a third-generation implantable cardioverter-defibrillator implanted with thoracotomy and nonthoracotomy lead systems was evaluated in a multicenter international study. BACKGROUND: The clinical impact of transvenous leads for nonthoracotomy implantation and pacing for bradyarrhythmias and tachyarrhythmias in implantable cardioverter-defibrillator systems is not well defined. METHODS: The safety of the implantation procedure and clinical outcome of 1,221 patients with symptomatic and life-threatening ventricular tachyarrhythmias who underwent implantation of a third-generation cardioverter-defibrillator using either a thoracotomy approach with epicardial leads (616 patients) or a nonthoracotomy approach with endocardial leads (605 patients) in a nonrandomized manner was analyzed. The implantable cardioverter-defibrillator system permitted pacing, cardioversion, defibrillation, arrhythmia event memory and noninvasive tachycardia induction. RESULTS: Successful implantation of an endocardial lead system was achieved in 605 (88.2%) of 686 patients and an epicardial system in 614 (99.7%) of 616 (p < 0.05). Perioperative 30-day mortality rate was 0.8% (1.8% including crossovers) in endocardial implant recipients compared with 4.2% (p < 0.001) in epicardial implant recipients (3.6% without crossovers, p < 0.05, respectively). Implantation mortality risk was significantly lower for nonthoracotomy systems irrespective of left ventricular ejection fraction or New York Heart Association functional class. Pacing therapies prevented need for cardioversion or defibrillation shocks in 89% of all ventricular tachycardia episodes and were comparably effective for both lead systems. Total survival rate at 2 years was significantly higher in endocardial (87.6%) than epicardial (81.9%) lead recipients (p < 0.001). Elimination of perioperative mortality from the analysis demonstrated comparable survival in both groups (p > 0.2). CONCLUSIONS: Third-generation cardioverter-defibrillators with monophasic waveforms can be successfully implanted with epicardial (99.7%) and endocardial (88.2%) lead systems. We conclude that endocardial leads should be the implant technique of first choice. Improved patient management and tolerance for device therapy is achieved with the addition of antitachycardia pacemaker capability in these systems.