Metabolic Response to the Initiation of Heart Failure Therapy

Inclusion Criteria: * ability to give written informed consent * Heart failure New York Functional class (NYHA) II-IV with duration more than 3 months (regardless ejection fraction, universal definition of HF) * NTproBNP more than 125 pg/ml at screening (Universal definition of HF) * O2 sat more than 90% Exclusion Criteria: * Previous SGLT2 inhibitor therapy or i.v., iron therapy in past 3 months (for SGLT2i arm) * Previous sGC stimulator (for sGC arm), or previous ARNI (for ARNI arm), or previous SGLT2i, sGC or ARNI for control group. * Coronary artery bypass grafting (CABG), cardiac resynchronisation therapy (CRT), STEMI, valve replacement, in past 3 months, or planned within next 3 months * Blood loss needing transfusion in past 3 months * Clinical instability (including HF hospitalization) in the past 1 month * Myelodysplasia, chronic hemolysis, erythropoetin therapy * Systemic inflammatory condition (lupus, rheumatoid arthritis...) or infection * Uncontrolled cancer * Chronic kidney disease (CKD) grade 4-5 * Severe anemia with Hgb less than 90 g/L * No chronic exposure to hypoxia (severe chronic obstructive pulmonary disease, obstructive sleep apnoea, long-term oxygen therapy) * History of SGLT2i allergy or intolerance * Repeated genitourinary infection