Association between Age and Early Mortality Risk after Implantable Cardioverter Defibrillator Implantation within The Veteran Affairs Health System

Abstract

Background Implantable cardioverter-defibrillator (ICD) therapy improves outcomes in patients with heart failure (HF) but current guidelines advise against placement of ICDs in patients with a life expectancy of less than 1 year. We examined the association between age and early mortality rate in patients who underwent primary or secondary prevention ICD in the Veterans Affairs (VA) Health System. Methods The analysis included US veterans with a diagnosis of heart failure and reduced ejection fraction (HFrEF) and a new implantation of primary or secondary prevention ICD. Patients treated nationwide in the VA-Health System from January 2007 to January 2015 were included. Diagnosis of HFrEF and ICD implantation was established through ICD9-codes. Mortality data were obtained fromthe VA's death registry. The patient cohort was divided in age quartiles and the 1-year and 8-year all-cause mortality were examined. Results A total of 17,901 patients with HFrEF and new ICD placement were identified. Distribution of age across quartiles (Q) was as following: Q1 23-61 years, mean 56; Q2 61-67 years, mean 64; Q3 67-76 years, mean 71; Q4 76-99 years, mean 82. The comorbidity burden (i.e. coronary artery disease, atrial fibrillation, chronic kidney disease and diabetes mellitus) was higher in Q3 and Q4 compared to Q1 and Q2. One-year and 8-year mortality are presented in the Figure . In the Q4 group, 32% of patients died within 1 year. Higher age quartiles were associated with significantly worse 1 and 8-year mortality when compared to Q1 (p Conclusion Elderly veterans with HFrEF and a new ICD implantation experience a high early mortality. Knowledge of clinical features associated with early mortality in the elderly population could help in the selection of appropriate ICD candidates in the VA population.