Is It Safe to Initiate/Optimize the Medication of HFrEF Patients During Hospitalization for Acute Decompensation?

<b>Background:</b> Current guidelines emphasize the importance of initiating or optimizing the four pillars of heart failure with reduced ejection fraction (HFrEF) therapy-beta-blockers (BB), mineralocorticoid receptor antagonists (MRA), angiotensin receptor-neprilysin inhibitors (ARNI), and sodium-glucose cotransporter-2 inhibitors (SGLT2i)-during hospitalization for acute decompensation. This study compares clinical characteristics and outcomes in HFrEF patients hospitalized for decompensated heart failure based on whether they were newly initiated on or were already receiving at least one of these four pillars. <b>Methods:</b> This prospective observational study included 203 HFrEF patients hospitalized for acute decompensation. Patients were divided into two groups: Group A (<i>n</i> = 126), not receiving any of the four pillars prior to admission, and Group B (<i>n</i> = 77), receiving at least one. Clinical and biological parameters were evaluated during hospitalization, with outcomes including changes in weight, blood pressure, heart rate, renal function (serum creatinine), electrolyte levels (sodium, potassium), and 30-day mortality. Statistical analyses included the non-parametric Mann-Whitney test and Chi-squared test. <b>Results:</b> Baseline characteristics (age, gender, LVEF, NT-proBNP) were similar between the two groups. No significant difference was observed in 30-day mortality (Group A: 7.14%, Group B: 5.55%, <i>p</i> = 0.74). Both groups experienced significant improvements in systolic and diastolic blood pressure and heart rate during hospitalization (<i>p</i> < 0.05). While serum creatinine levels remained stable in both groups, creatinine dynamics (Δcreatinine) were significantly different (<i>p</i> = 0.02), with Group B exhibiting a higher increase. The improvement in ejection fraction was more pronounced in Group A (<i>p</i> = 0.057) compared to Group B. Both groups demonstrated significant improvements in NYHA functional class (<i>p</i> < 0.001). In Group B, the use of MRAs and SGLT2 inhibitors significantly increased during hospitalization (<i>p</i> = 0.01 and <i>p</i> < 0.001, respectively). <b>Conclusions:</b> The initiation or optimization of the four pillars of HFrEF therapy during hospitalization for acute decompensation is feasible and well-tolerated. Early intervention leads to improvements in clinical parameters and functional status, supporting guideline recommendations for in-hospital initiation or optimization of HFrEF therapy. Special consideration should be given to renal function when optimizing therapy.