Higuchi S, et al. - Although guidelines recommend that patients with heart failure with reduced ejection fraction (HFrEF) should be treated with renin-angiotensin system (RAS) inhibitors, researchers analyzed the long-term effectiveness of RAS inhibitors in HFrEF patients with moderate-to-severe chronic kidney disease (CKD), defined as an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m². Participants in the study included patients hospitalized in five Japanese teaching hospitals for acute heart failure. In total, there were 553 patients. Findings suggested an association of RAS inhibitors with a reduction in mortality in stage 3B CKD in HFrEF patients with CKD, but the association in stage 4 or 5 CKD is less clear.