A single-center analysis of guideline-directed medical therapy in patients with heart failure with mildly reduced or preserved ejection fraction according to current heart failure guidelines

Background: Recent landmark trials have shown that several pharmacologic therapies improve outcomes in patients with heart failure with mildly reduced ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF), leading to updates in heart failure (HF) management guidelines. However, real-world adherence to guideline-directed medical therapy (GDMT) in these populations remains uncertain. This study evaluated GDMT prescription patterns in patients with HFmrEF or HFpEF based on the 2022 Korean Heart Failure Society guidelines.Methods: This single-center observational study included patients newly diagnosed with HF between January and December 2023, identified using International Classification of Diseases codes. Patients without recent echocardiographic or N-terminal pro–brain natriuretic peptide data, those with reduced ejection fraction, or those with end-stage renal disease were excluded. Electronic medical records were reviewed to assess GDMT prescription rates.Results: Among 615 patients (mean age, 68.9 years; 52.4% female), 568 had HFpEF and 47 had HFmrEF. Common comorbidities included hypertension (75.5%), diabetes mellitus (50.9%), ischemic heart disease (43.7%), and chronic kidney disease (22.6%). Overall prescription rates were 73.3% for renin–angiotensin system inhibitors, 83.7% for beta-blockers, 41.1% for mineralocorticoid receptor antagonists (MRAs), and 42.9% for sodium–glucose cotransporter 2 inhibitors (SGLT2is). SGLT2i use was significantly higher in patients with diabetes than in those without (71.6% vs. 13.2%; p<0.001). Angiotensin receptor–neprilysin inhibitors and MRAs were more frequently prescribed in HFmrEF than HFpEF. Beta-blocker use was lower in patients aged ≥75 years.Conclusions: A substantial gap persists between guideline recommendations and real-world GDMT use in patients with HFmrEF and HFpEF, particularly for SGLT2is. Multicenter studies are warranted to further characterize and address this treatment gap.