Trends in Comorbidities and 1-Year Mortality after Implantable Cardioverter Defibrillator Implantation Within The Veteran Affairs Health System

Abstract

Background Implantable cardioverter-defibrillator (ICD) therapy improves mortality in patients with heart failure (HF) but current guidelines advise against implantation of ICDs in patients with a life expectancy of less than 1 year. We examined the 1-year mortality rate and burden of comorbid diseases 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. We described the Charlson Comorbidity Index (high value = high comorbid index) and all-cause mortality rates within 1 year of device implantation. Results We identified 17,901 VA patients with HFrEF and new ICD implantation. Patients were on average 66 ± 10 years old, predominantly male (99%), and had a history of coronary artery disease (81%), chronic kidney disease (42%) and diabetes mellitus (56%). Average Charlson Comorbidity Index was 3.0 (SD ±1.5). The Comorbidity Index gradually decreased from 2007 to 2014 from 3.1 to 2.8 which represented a statistically significant decrease after the year 2011 (p 0.05) (Figure). Discussion Amongst patients with HFrEF and a new ICD implantation, we found a high 1-year mortality rate. The 1-year mortality rate remained unchanged over an 8-year period even despite a slowly decreasing burden of comorbid disease among ICD patients over the same time period. Future work needs to identify patients with a reduced chance of survival and apply specific risk prediction scores for the selection of appropriate ICD candidates in the VA population.