The study objective is to observe and measure clinical outcomes, urine output, and safety events occurring during standard medical treatment of ADHF patients deemed to have insufficient diuretic response.

Inclusion Criteria:

1. Subject is >18 and < 85 years of age.

2. Subject is hospitalized with primary diagnosis of ADHF.

3. N-terminal-pro-brain natriuretic peptide (NT-proBNP) ≥1,600 pg/m or BNP≥400 pg/mL.

4. Evidence of fluid overload as indicated by 2 or more of the following criteria:

   1. peripheral edema ≥ 2+
   2. radiographic pulmonary edema or pleural effusion
   3. enlarged liver or ascites
   4. pulmonary rales or paroxysmal nocturnal dyspnea, or orthopnea
   5. Jugular venous distention > 7 cmH2O

5. Subject insufficiently responds to IV diuretic therapy

Exclusion Criteria:

1. Systolic blood pressure <90 mmHg at the time of screening.
2. Acute myocardial infarction or acute coronary syndrome or cardiogenic shock or pleural synthesis within past 7 days or cardiovascular intervention within past 4 days.
3. Known LVEF < 15% by echocardiography within 1 year prior to enrolment.
4. Complex congenital heart disease (e.g., Tetralogy of Fallot subjects, single ventricle physiology).
5. Known active myocarditis, hypertrophic obstructive cardiomyopathy, constrictive pericarditis or cardiac tamponade.
6. Severe Aortic valvular disorder (i.e., hemodynamically relevant valvular diseases such as severe stenosis \severe regurgitation) or Severe mitral disease with planned intervention.
7. Evidence of active systemic infection documented by either one of the following: fever >38°C/100°F, or ongoing uncontrolled infection (i.e., inflammatory parameters not decreasing despite > 48 hours of antibiotic treatment).
8. Moribund subject or subject with severe or deteriorating damage in more than 3 critical body systems, based on investigator's clinical judgement.

Acute Heart Failure Patients with Insufficient Response to Diuretics