Implantable cardioverter defibrillator implantation rates in the Olmsted County, Minnesota, population: 1989-1999

Although the efficacy of implantable cardioverter defibrillators (ICDs) has been demonstrated in randomized clinical trials, implantation and survival rates have not been reported for a defined population. We performed a retrospective cohort analysis of Olmsted County, Minnesota residents (n = 70) who received their first ICD between 1 January 1989 and 31 December 1999. The ICD implantation rate increased from approximately 2.5/100,000 (95% confidence interval [CI], 0.9-4.1) in the first 4 years to 11.5/100,000 (95% CI, 6.7-16.2) in the last 2 years. Twenty-three patients (33%) received an appropriate ICD shock during the observation period. Based on these data, ICDs are estimated to reduce total mortality rates in this population by 0.3%. We conclude that, in patients drawn from a community setting with AHA/ACC class I indications for ICD implantation, implantation of ICDs appears to be highly efficacious in aborting potentially fatal events.