SCD for CRS in Congestive Heart Failure (CHF) (No Left Ventricular Assist Device)

Inclusion Criteria: * Primary hospitalization for acute decompensated chronic systolic heart failure as defined: * Left ventricular ejection fraction ≤35% as confirmed by baseline imaging procedure. * New York Heart Association (NYHA) class III or IV chronic (≤ 90 days) systolic heart failure, with failure to respond to optimal medical therapy (beta blocker, Angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blockers (ARB) or valsartan/sacubitril, aldosterone antagonist, unless not tolerated or contraindicated, and loop diuretic, as needed) for 45 of the last 60 days. * Baseline Estimated Glomerular Filtration Rate (eGFR)\*\* ≥ 40 ml/min/1.73 m2 (baseline defined as the highest known eGFR within 90 days of study enrollment) * Worsening renal failure (WRF), defined for the purposes of this study as increase serum creatinine ≥ 0.5 mg/dL from baseline (baseline defined as the lowest known serum creatinine within 90 days of study enrollment) * Cardiorenal syndrome is the most likely explanation for WRF * Persistent signs and /or symptoms of congestion (peripheral edema, dyspnea, pulmonary rales, neck vein distension) despite optimal medical therapy including intravenous diuretic therapy and an estimated need for greater than 5 kg. of fluid removal. For the purposes of this study, optimal intravenous diuretic therapy is defined as: * Furosemide equivalent total daily dose of 240 mg (furosemide 40mg=1mg bumetanide) * Furosemide equivalent dose given either as a single or multiple intravenous bolus or continuous infusion * A furosemide equivalent total daily dose \<240 mg if the dose has resulted in \>3000 ml urine output/24 hours Exclusion Criteria: * Prior sensitivity to dialysis device components * Individual with known hypersensitivity to citrate * Bacteremia or possible infection, as evidence by fever, white blood cell count \> 10,000/microliter, or any other signs of acute or chronic infection, and any patient receiving antibiotic or antiviral therapy. * Active malignancy requiring chemotherapy, biological therapy or radiation therapy. * The use of intravenous iodinated contrast agent within the prior 72 hours or the anticipated use of such an agent during SCD therapy. * Need for intravenous vasopressor (i.e., phenylephrine, vasopressin), intravenous. vasoconstricting inotrope (i.e., norepinephrine or epinephrine) or dopamine \> 3 mcg/kg/min. (Note: use of vasodilating inotropes \[i.e., dobutamine and milrinone\] or dopamine at ≤ 3 mcg/kg/min will not preclude study inclusion). * Persistent systolic blood pressure (SBP) \< 80 mmHg. * White blood cell (WBC)\<4000/microliter. * Platelets \< 50,000/microliter. * Serum creatinine \> 4 mg/dL or receiving dialysis / continuous renal replacement therapy (CRRT) * Acute coronary syndrome within the past month. * Women who are pregnant, breastfeeding a child, or trying to become pregnant. * Subject not able to sign informed consent. * Use of any other investigational drug or device within the previous 30 days * Concurrent enrollment in another interventional clinical trial. Patients enrolled in clinical studies where only measurements and/or samples are taken (i.e., no test device or test drug used) are allowed to participate.