RESULTS OF THE INTERNATIONAL STUDY OF THE IMPLANTABLE PACEMAKER CARDIOVERTER-DEFIBRILLATOR - A COMPARISON OF EPICARDIAL AND ENDOCARDIAL LEAD SYSTEMS

Background The purpose of the present report was to document clinical experience derived from the implantation of 2834 epicardial and endocardial cardioverter-defibrillators (ICDs) in 2807 patients who were followed for almost I year and to compare he results obtained with the two systems. Methods and Results Patients in the two groups had similar clinical characteristics. More than half of the patients had a total of almost 50 000 spontaneous ventricular tachyarrhythmias that were terminated with equal success (approximate to 98%) by epicardial and endocardial ICDs. Lead dislodgement and pocket infection occurred more often with the endocardial than with the epicardial ICD, whereas perioperative mortality was higher with the epicardial ICD than with the endocardial ICD. Mortality from sudden cardiac death was 1.4% in the epicardial ICD group and 0.6% in the endocardial ICD group at 1 year (P=.069). Overall mortality at 1 year was 12.2% and 6.9% for the epicardial and endocardial groups, respectively (P<.001), reflecting the higher surgical mortality for the epicardial system. Conclusions The endocardial ICD is as effective as the epicardial ICD but incurs lower perioperative mortality.