CLINICAL OUTCOME OF PATIENTS WITH MALIGNANT VENTRICULAR TACHYARRHYTHMIAS AND A MULTIPROGRAMMABLE IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IMPLANTED WITH OR WITHOUT THORACOTOMY - AN INTERNATIONAL MULTICENTER STUDY

Objectives. The long term efficacy and safety of a third-generation im plantable cardioverter-defibrillator implanted with thoracotomy and no nthoracotomy lead systems was evaluated in a multicenter international study. Background. The clinical impact of transvenous leads for nonth oracotomy implantation and pacing for bradyarrhythmias and tachyarrhyt hmias in implantable cardioverter defibrillator systems is not well de fined. Methods. The safety of the implantation procedure and clinical outcome of 1,221 patients with symptomatic and life-threatening ventri cular tachyarrhythmias who underwent implantation of a third generatio n cardioverter defibrillator using either a thoracotomy approach with epicardial leads (616 patients) or a nonthoracotomy approach with endo cardial leads (605 patients) in a nonrandomized manner was analyzed. T he implantable cardioverter defibrillator system permitted pacing, car dioversion, defibrillation, arrhythmia event memory and noninvasive ta chycardia induction. Results. Successful implantation of an endocardia l lead system was achieved in 605 (88.2%) of 686 patients and an epica rdial system in 614 (99.7%) of 616 (p < 0.05). Perioperative 30 day mo rtality rate was 0.8% (1.8% including crossovers) in endocardial impla nt recipients compared with 4.2% (p < 0.001) in epicardial implant rec ipients(3.6% without crossovers, p < 0.05, respectively). Implantation mortality risk was significantly lower for nonthoracotomy systems irr espective of left ventricular ejection fraction or New York Heart Asso ciation functional class. Pacing therapies prevented need for cardiove rsion or defibrillation shocks in 89% of all ventricular tachycardia e pisodes and were comparably effective for both lead systems. Total sur vival rate at 2 years was significantly higher in endocardial (87.6%) than epicardial (81.9%) lead recipients (p < 0.001). Elimination of pe rioperative mortality from the analysis demonstrated comparable surviv al in both groups (p > 0.2). Conclusions. Third-generation cardioverte r defibrillators with monophasic waveforms can be successfully implant ed with epicardial (99.7%) and endocardial (88.2%) lead systems. We co nclude 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.