The importance of assessing venous congestion in heart failure patients is widely acknowledged, but its study is hampered by the lack of a practical evaluation tool. Venous excess ultrasound score (VExUS) is a promising noninvasive ultrasound-guided modality that can detect and objectify clinically significant organ congestion. VExUS congestion grading score was still not formally validated in patients with AHF, as there is limited data on its clinical application in this group of patients.

It is currently unknown whether changes in systemic venous congestion, assessed by venous excess ultrasound score (VExUS), are associated with worsening renal function, reduced diuretic and natriuretic response, and poor prognosis in patients with acute decompensation of heart failure (AHF).

This prospective, observational, single-center study included patients admitted to the intensive care unit with AHF. At admission all patients undergo bedside Doppler ultrasound of inferior vena cava, hepatic, portal and renal veins to determine blood flow patterns. Congestion was graded with the VExUS score (grade 0, grade 1, grade 2, grade 3). Sodium concentration in a spot urine sample was assessed in 1 hour after first standard intravenous loop diuretic administration. The primary endpoint was the development of acute kidney injury (AKI), defined as oligoanuria (diuresis rate <0.5 ml/kg/hour for 6 hours) and an increase of serum creatinine >26 µmol/l within a 48-hour period or 50% from baseline creatinine within a week. The secondary endpoints were in-hospital mortality, change in spot urine sodium content <50 mmol/l and development of diuretics resistance (defined as the need to double starting dose of intravenous furosemide in 6 hours without adding a different class of diuretic agents).

Inclusion Criteria:

• Acute decompensation of heart failure (diagnosis was based on the European Society of Cardiology (ESC) heart failure guidelines, with patients presenting with dyspnoea at rest or with minimal exertion and signs and symptoms of congestion (rales on chest auscultation, peripheral oedema, swelling of the cervical veins, hepatomegaly, ascites, hepatojugular reflux) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) > 1000 pg/ml

Exclusion Criteria:

• Chronic renal replacement therapy or glomerular filtration rate < 15 ml/min/1.73m 2 (chronic kidney disease Epidemiology Collaboration (CKD)-EPI)
• Cirrhosis with portal hypertension
• Acute myocardial infarction according to The Fourth Universal Definition of Myocardial infarction
• Pulmonary embolism
• Sepsis (according to The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3))
• Endotracheal intubation at the time of admission
• Pregnancy or breastfeeding
• Aortic dissection
• Active cancer
• Neurological or mental disease during exacerbation
• Refusal to sign an informed consent form, inadequate acoustic window

The study involved patients over 18 years of age admitted to the hospital with AHF and requiring intravenous administration of loop diuretics. Diagnosis was based on the European Society of Cardiology (ESC) HF guidelines, with patients presenting with dyspnoea at rest or with minimal exertion and signs and symptoms of congestion (rales on chest auscultation, peripheral oedema, swelling of the cervical veins, hepatomegaly, ascites, hepatojugular reflux) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) >1000 pg/ml.

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