One-year mortality after implantable cardioverter-defibrillator placement within the Veterans Affairs Health System

Aims: Implantable cardioverter-defibrillator (ICD) therapy reduces mortality in patients with heart failure and current guidelines advise implantation of ICDs in patients with a life expectancy of >1 year. We examined trends in all-cause mortality in patients who underwent primary or secondary prevention ICD placement in the Veterans Affairs (VA) Health System.

Methods and results: US veterans receiving a new ICD placement for primary or secondary prevention of sudden cardiac death between January 2007 and January 2015, who had heart failure with reduced ejection fraction (HFrEF) were included in the analysis. We assessed all-cause mortality 1 year post-ICD implantation. ICD implantation and HFrEF diagnosis were established with associated ICD-9 codes. The VA death registry was utilized to identify mortality rates following ICD placement. Results were subsequently age-stratified. There were 17 901 veterans with HFrEF with ICD placement nationwide. There was no statistically significant difference in 1-year mortality from 2007 (13.1%) to 2014 (13.4%, P > 0.05). There was a significant increase in 1-year mortality in patients in the oldest age quartile (81.6 years, 32.3% mortality) compared to the youngest quartile (55.5 years, 7% mortality). The finding of diverging clinical outcomes extended to the 30-day but also 8-year mark.

Conclusions: Our data suggest there is a high 1-year mortality in aging HFrEF patients undergoing primary and secondary prevention ICD placement. This highlights the importance of developing better predictive models for mortality in our ICD eligible patient population.