Comparison of Pre- and Post-discharge Initiation of LCZ696 Therapy in HFrEF Patients After an Acute Decompensation Event

Inclusion Criteria: 1. Patients hospitalized due to acute decompensated HF episode (ADHF) as primary diagnosis) and consistent Signs \& Symptoms 2. Diagnosis of HF New York Heart Association class II-to-IV and reduced ejection fraction: Left ventricular ejection fraction ≤ 40% at Screening 3. Patients did not receive any IV vasodilators (except nitrates), and/or any IV inotropic therapy from the time of presentation for ADHF to Randomization 4. Stabilized (while in the hospital) for at least 24 hours leading to Randomization. 5. Meeting one of the following criteria: * Patients on any dose of ACEI or ARB at screening * ACEI/ARB naïve patients and patients not on ACEI or ARB for at least 4 weeks before screening. Exclusion Criteria: 1. History of hypersensitivity to the sacubitril, valsartan, or any ARBs, NEP inhibitors or to any of the LCZ696 excipients. 2. Symptomatic hypotension and/or a SBP below 110 mm Hg or SBP above 180 mm Hg prior to randomization 3. End stage renal disease at Screening; or estimated GFR below 30 mL/min/1.73 m2 (as measured by MDRD formula at Randomization. 4. Serum potassium above 5.4 mmol/L at Randomization. 5. Known history of hereditary or idiopathic angioedema or angioedema related to previous ACE inhibitor or ARB therapy 6. Severe hepatic impairment, biliary cirrhosis and cholestasis