BACKGROUND: Automated 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. METHODS: Linked 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. RESULTS: Between 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 100000 in 1995 to 14.9 in 100000 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. CONCLUSIONS: Implantable 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.
BACKGROUND: Automated 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. METHODS: Linked 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. RESULTS: Between 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 100000 in 1995 to 14.9 in 100000 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. CONCLUSIONS: Implantable 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.