Use and long-term outcomes of implantable cardioverter-defibrillators, 1990 to 2009

BackgroundAutomated implantable cardioverter-defibrillators (ICDs) have become standard therapy for patients at high risk for sudden cardiac death. Linked data allow examination of trends in use and long-term survival after ICD implantation in an adult population.MethodsLinked state-wide person-based data on hospital admissions and deaths from 1980 to 2009 were used to identify incident cases of ICD implantation. Population rates were calculated using census data. Kaplan-Meier techniques were used to describe cumulative survival. Cox regression models were used to determine the factors associated with the outcomes.ResultsBetween 1988 and 2009, 1593 devices were implanted in patients in Western Australia, rising from 2 in 1988 to 245 in 2009; standardized population rates rose from 0.8 in 100 000 in 1995 to 14.9 in 100 000 in 2009. Mean age rose from 52.6 (SD 11.6) to 64.1 (11.4) years. Ventricular tachycardia (23%), cardiomyopathy (18%), and heart failure (16%) were the most frequent principal diagnoses. Ischemic heart disease was present in 49% of patients. Five-year cumulative survival was 0.74 (SE 0.01), and at 10 years, 0.53 (SE 0.03); median survival was 11.3 years. Readmission within a year, older age, heart failure, device complications, and chronic ischemic heart disease were associated with poorer survival.ConclusionsImplantable cardioverter-defibrillator use in adults at risk for sudden cardiac death has grown rapidly. Readmission within 12 months of discharge is associated with worse medium and long-term mortality. Survival for most patients younger than 65 years exceeds 10 years and 5 years for those aged ≥75 years.