Table 1.

Eligibility criteria

Inclusion criteria 1. Hospitalization for ADHF with dyspnoea ≥NYHA III, peripheral oedema, and pulmonary congestion (rales on auscultation or pulmonary vascular congestion on chest radiograph) 2. Age ≥ 18 years 3. NT‐proBNP >300 ng/L within 24 h after admissiona 4. Sufficient ultrasound visualization to evaluate IVC 5. IVC max >2.1 cm and IVCCI ≤50% in the baseline assessment within 24 h after admission 6. Informed consent

Exclusion criteria 1. Cardiogenic shock with systolic blood pressure <90 mmHg plus end‐organ hypoperfusion 2. ADHF due to significant arrhythmiasb 3. Severe pulmonary disease as primary cause of dyspnoea 4. Simplified modification of diet in renal disease estimated glomerular filtration rate < 30 mL/min/1.73 m² 5. Need for non‐invasive or invasive ventilation support at baseline 6. Pregnancy 7. Participation in another interventional trial

As determined by the local laboratory.

Significant arrhythmias are defined as (i) third‐degree atrioventricular block or sinus arrest with junctional or ventricular escape rhythm, (ii) sustained ventricular tachycardia, or (iii) other sustained arrhythmias leading to decompensation other than atrial fibrillation as judged by the treating physician.

ADHF, acute decompensated heart failure; IVC, inferior vena cava; IVCCCI, inferior vena cava collapsibility index; NT‐proBNP, N‐terminal pro‐brain natriuretic peptide; NYHA, New York Heart Association functional class.