Utilization and outcomes of the implantable cardioverter defibrillator, 1987 to 1995

Background. The patterns of adoption of the implantable cardioverter defibrillator (ICD) and the outcomes of its use have not been well documented in general, unselected populations. The purpose of this study was to document the impact of the ICD in widespread clinical practice. Methods. We identified ICD recipients by use of the hospital discharge databases of Medicare beneficiaries for 1987 through 1995 and of California residents for 1991 through 1995. The index admission for each patient was linked to previous and subsequent admissions and to mortality files to create a longitudinal patient profile. Results. The rate of ICD implantations increased > 10-fold between 1987 and 1995, as both the number of hospitals performing the procedure and the volume of ICD implantations per hospital rose. Mortality rates within 30 days of ICD implantation decreased from 6.0% to 1.9%, and mortality rates within 1 year fell from 19.3% to 11.4%. Surgical interventions to revise or replace the ICD within the first year remained about 5%, however, and cumulative expenditures at 1 year ($46,000-$51,000) changed very little. ICD implantation rates varied > 3-fold among different regions of the United States. Conclusions. ICD use has expanded markedly during the study period, with improved mortality rates, but medical expenditures and rates of surgical revision remain high for ICD recipients.