A Clinical Trial to Define the Best Strategy for the Management of Heart Failure in Elderly Patients

Inclusion Criteria: * Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. * Provision of informed consent form prior to any study specific procedures, sampling and analysis. * Individuals must be ≥ 70 years of age at the time of signing the informed consent form. * Individuals must have a confirmed diagnosis of Heart Failure (HF) according to clinical practice guidelines NYHA functional class I-III (with HFrEF or HFpEF). * Individuals must have previously been admitted to hospital due to HF decompensation requiring intravenous diuretics. * Individuals must have been stabilised for at least 24-48h of their HF decompensation before randomisation. * Individuals must have a confirmed diagnosis of Chronic Kidney Disease defined as a renal impairment of eGFR less than 60ml/min/1.73 m2. * Individuals receiving background standard of care for HF and treated according to international guidelines. Specific treatment should include RAASi and/or MRA treatment and at least should have been stable for ≥ 4 weeks at maximum tolerated doses. * Patients on RAASi blocker treatment with less than or equal to 75% of the maximum recommended dose. * Hyperkalemic patients (sK+ 5.1-5.9 mmol/L at screening / study enrolment) or Normokalemic patients at risk of developing HK defining as having a history of hyperkalaemia (sK+ \>5.0 mEq/L) within the prior 24 months and sK+ ≥4.5 mEq/L ≤ 5.1 mEq/L at inclusion Exclusion Criteria: * Limited life expectancy (less than 1 year) according to clinician's criteria, such as but not limited to malignancy, with life expectancy of less than 2 years based on investigator's clinical judgement. * sK \>6 mEq/litre or \<4.5mEq/litre or history of hypokalemic episodes (S-K\<3.5 mEq/L) during the last year. * Patients on haemodialysis or haemofiltration * NYHA functional class IV * Patients undergoing treatment with potassium binders. * Active tumour undergoing chemotherapy or metastasis or malignancy requiring treatment. * Symptomatic or uncontrolled atrial fibrillation despite treatment, or asymptomatic sustained ventricular tachycardia. Subjects with atrial fibrillation controlled by medication are permitted. * QTc(f) \> 550 msec. * History of QT prolongation associated with other medications that required discontinuation of that medication. * Congenital long QT syndrome. * Prior history of hypersensitivity to a RAAS blocker drug, including but not limited to development of angioedema, icterus, hepatitis, or neutropenia or thrombocytopenia requiring treatment modification. Addison's disease or other causes of hypoaldosteronism. * Patients with a known hypersensitivity to SZC or any of the excipients of the product. * Individuals treated with potassium binding resins such as sodium polystyrene sulfonate (SPS, e.g. Kayexalate®) or calcium polystyrene sulfonate (CPS; e.g. Resonium®) or the cation exchange polymer, patiromer sorbitex calcium (Veltassa®) within 7 days prior to the first dose of study drug. * Treated with potassium supplements within 7 days prior to randomization. 15. Positive hepatitis C antibody hepatitis B virus surface antigen or hepatitis B virus core antibody, at screening. * Known to have tested positive for human immunodeficiency virus. * Known history of drug or alcohol abuse within 3 year of screening. * Involvement in the planning and/or conduct of the study (applies to both Investigator staff and/or staff at the study site). * Judgment by the investigator that the subject should not participate in the study if the subject is unlikely to comply with study procedures, restrictions and requirements. * Previous enrolment in the present study. * Participation in another clinical study with an investigational product during the last 3 months.