Objective: This study aims to investigate the guideline adherence and prognostic role of guideline recommended heart failure (HF) therapies in patients hospitalized with heart failure with mildly reduced ejection fraction (HFmrEF). 

Background: Limited data regarding the guideline adherence and prognostic impact of different pharmacotherapies in patients with HFmrEF is available. 

Methods: A large retrospective registry was used including all consecutive hospitalized patients with HFmrEF (i.e., left ventricular ejection fraction (LVEF) 41 – 49%) from 2016 to 2022 according to current European guidelines. The prescription rates of angiotensin-converting enzyme and receptor blockers (ACEi/ARB), beta-blockers (BB), mineralocorticoid receptor antagonists (MRA), sodium glucose linked transporter 2 inhibitors (SGLT2i) and angiotensin receptor-neprilysin inhibitor"(ARNi) was assessed. The different pharmacotherapies were compared with regard to prognostic outcomes. The primary endpoint was the first heart-failure related re-hospitalization at 3 years. Secondary endpoints comprised amongst others cardiovascular re-hospitalization. Kaplan-Meier, uni- and multivariable Cox regression analyses were applied for statistics.

Results: 775 consecutive patients with HFmrEF surviving index hospitalization were included. Of those, 73% were discharged on ACEi/ARB, followed by BB (26%), 14% MRA. In contrast, SGLT2i (3%) and ARNI (1%) were only administered in a minor part. No prognostic impact of BB (10% vs. 7%; log rank p=0.218; HR=1.474; 95% CI 0.792-2.742; p=0.220), ACEi/ARB (9% vs. 10%; log rank p=0.444; HR=0.822; 95% CI 0.497-1.359; p=0.445), SGLT2i (8% vs. 9%; log rank p=0.821; HR=0.851; 95% CI 0.209-3.470; p=0.445), MRA (8% vs. 9%; log rank p=0.748; HR=0.892; 95% CI 0.443-1.794; p=0.748) and ARNi (0% vs. 9%; log rank p = 0.558) regarding any of the evaluated prognostic outcomes (i.e. heart failure related and cardiovascular re-hospitalization at 3 years) was observed.