Introduction: Renal congestion is a factor of unfavo-rable outcome in patients hospitalized for acute heart failure. Literature data found persistent hyponatremia to be an independent risk factor for mortality and re-hospitalization in patients diagnosed with heart failure.

Objective: We aimed to assess the impact of diuretics on renal function and electrolyte levels of patients with heart failure.

Methods: A retrospective study was performed on pa-tients diagnosed with heart failure who were admitted to our clinic during a 12-month period. Patient demo-graphics, medical history, blood works, echocardio-graphy results and data on in-hospital treatment were collected. Parametric and non-parametric tests were obtained using SPSS, version 20.

Results: A total of 100 patients were enrolled, 50% had heart failure with preserved ejection fraction (HFpEF) and 50% had heart failure with reduced ejection frac-tion (HFrEF). The mean age was 71.10 ± 10.93 y.o. and HFpEF were older (74.66 ± 9.44 vs. 67.54 ± 11.24) and with a female predominance (82% vs. 36%). Maximum urea levels reached while in hospital were differently distributed among the two groups (HFpEF 55.99 ± 33.41 vs. 71.87 ± 43.06, p=0.031); likewise for mini-mum plasma sodium levels (140.66 ± 5.79 vs. 137.64± 9.40, p=0.013), but not maximum creatinine which did not reach statistical significance despite the diffe-rence between subgroups (1.04 ± 0.53 vs. 1.31 ± 0.46, p=0.180). Minimum sodium and total spironolactone dose correlated significantly (r=0.211, p=0.047) as well as maximum urea and total oral furosemide (r=0.297, p=0.005).

Conclusions: We interpreted the need for higher doses of diuretics in patients with reduced ejection fraction as a consequence of more prominent pulmonary and systemic congestion. IV furosemide is needed in order to control congestion, but careful titration of oral doses is advised so as to prevent dehydration.