Background: Diuretics are being used to reduce symptoms of congestion and fluid retention in heart failure patients but their effect has not been studied in randomized clinical trials. The data about positive or negative effect of loop diuretics depending on their dose is conflicting and controversial. The aim of this analysis is to evaluate whether the relatively small increase in the dose of furosemide can reduce the incidence of readmissions for acute heart failure decompensation and/or total mortality. Methods and results: We evaluated a total of 1119 patients admitted for ADHF who were discharged from the hospital back home in a stable condition. All surviving patients were followed up for at least two years. The primary endpoint was a combination of hospital readmissions for acute heart failure and overall mortality. The primary analysis showed significantly different characteristics and prognosis of patients who did not require any loop diuretic and those requiring furosemide dose >125 mg. Therefore, we compared a group of patients with low-dose furosemide (10-40 mg) with a group of patients with high-dose furosemide (41-125 mg) only. The higher dose of diuretics correlated well with disease severity (lower systolic blood pressure, more frequent chronic exertional dyspnea NYHA III, lower left ventricular ejection fraction, increased creatinine levels). Long-term mortality and the number of rehospitalizations were lower in the low-dose diuretic group (p = 0.037 and p = 0.036, respectively) but after adjustment using the propensity score matching the incidence of the primary endpoint was comparable in both groups. Conclusion: The dose of a loop diuretic recommended to patients with acute heart failure at hospital discharge correlates well with the severity of heart failure. When comparing the groups of patients with a higher dose of furosemide (41-125 mg) and a lower dose of furosemide (10-40 mg) we found that after adjustment using propensity score matching the higher dose of loop diuretic had a neutral effect on the incidence of the composite endpoint of overall mortality and/or readmission for ADHF. (C) 2017 The Czech Society of Cardiology. Published by Elsevier Sp. z o.o. All rights reserved.