Concentrated Saline Infusions and Increased Dietary Sodium With Diuretics for Heart Failure With Kidney Dysfunction

Inclusion Criteria: * Adult patients (age ≥18) admitted with CHF exacerbation with NYHA Class III-IV symptoms at screening. * Left ventricular ejection fraction \</= 45%, as determined by previous echocardiogram, left ventricular angiogram, or thallium myocardial imaging. * Estimated GFR \<60 ml/min/1.7m² with significant prerenal physiology as judged by prior documented volume mediated changes in renal function, a fractional excretion of urea \<35%, or a fractional excretion of sodium \<1%. For GFR 30-60: must have serum sodium \</= 135 mEq/L OR large home diuretic dose (total daily loop diuretic dose \>/= 120 mg/d in furosemide equivalents OR concomitant thiazide use). For GFR \<30: no additional criteria needed. Exclusion Criteria: * Admit estimated GFR \< 15mL/min or predicted need for chronic hemodialysis within the next 60 days. * Cause of acute kidney injury other than prerenal physiology. * No loop diuretic prior to admission or loop diuretic initiated within the 2 wks prior to admission. * Medicine or dietary noncompliance expected to prevent successful study participation. * \> 36hrs since presentation to screening. * Serum Na \> 145 mEq/L OR \< 120 mEq/L at screening. * Systolic blood pressure \> 180 mmHg at screening. * Presentation with acute coronary syndrome OR left heart catheterization planned at screening. * Current or impending respiratory failure at screening. * Current calcineurin inhibitor or nesiritide use. * Nephrotic-range proteinuria. * Clinical evidence for the presence of cirrhosis with bilirubin \>/= 2mg/dL or international normalized ratio (not on coumadin) \>/= 1.7. * Presence of another active medical issue which may prolong hospital admission or delay aggressive CHF therapy. * Participation in another interventional study. * Pregnancy. * Prisoners.