Impact of Finerenone in Patients with Heart Failure and Reduced/Mildly Reduced Ejection Fraction, Diabetes Mellitus, and Chronic Kidney Disease

<b>Background</b>: Heart failure (HF) remains a major global health challenge with substantial morbidity, mortality, and healthcare burden. Finerenone, a novel non-steroidal mineralocorticoid receptor antagonist (MRA), has demonstrated cardiovascular and renal benefits in patients with diabetes mellitus (DM) and chronic kidney disease (CKD), as well as reduced HF events, in patients with HF with preserved or mildly reduced ejection fraction (HFpEF/HFmrEF). However, its efficacy and safety in patients with HF with reduced EF (HFrEF) or HFmrEF, DM, and CKD, remain unclear. Notably, finerenone is currently reimbursed only for DM and CKD but not for HF itself. <b>Methods</b>: We conducted a retrospective, single-center study of patients with HFrEF/HFmrEF who received finerenone between August 2022 and June 2025. Clinical data were obtained 6 months before, at baseline, and 6 months after the initiation of finerenone. The primary outcome was the change in serum NT pro-B-type natriuretic peptide (BNP). <b>Results</b>: Among 37 patients screened, 22 who initiated finerenone on a de novo basis were included. Median age was 75 years, 73% were male, and all had DM and CKD, which are current indications of finerenone. NT pro-BNP decreased significantly during the on-treatment period compared with the pre-treatment period (<i>p</i> < 0.001). Left ventricular end-diastolic diameter and left ventricular ejection fraction remained unchanged during the pre-treatment period but improved significantly during the on-treatment period (<i>p</i> < 0.001 for both). Renal function and serum potassium remained stable during the whole study period (<i>p</i> > 0.05 for both). <b>Conclusions</b>: In this real-world study of patients with HFrEF/HFmrEF complicated by DM and CKD, finerenone was associated with significant improvements in NT pro-BNP and cardiac remodeling indices without worsening renal function or hyperkalemia.