Ambrosy AP, et al. - Researchers conducted this study on outpatients with HF and a reduced ejection fraction (HFrEF) (i.e. ≤ 35%) enrolled in HF-ACTION between April 2003 and February 2007 to compare outcomes between subjects randomized to aerobic exercise training vs usual care. Based on the presence of chronic kidney disease (CKD), defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m², categories of patients were formed. They noted a high prevalence of CKD among ambulatory HFrEF patients, and it was related to a poorer overall prognosis. Data showed the prevalence of CKD in these subjects was not associated with a differential response to aerobic exercise training.