Monitoring Oedema in Heart Failure to Improve Function and Reduce Hospitalisation Risk

Inclusion Criteria: Participants are eligible if they meet all General Criteria and at least one of Pathways A, B, or C. 1\. General Criteria (all participants must meet) * Aged ≥18 years, AND * Diagnosis of heart failure (any aetiology or LVEF classification), AND * Documented or patient-reported moderate to severe leg oedema, AND * Lives in the UK with a home environment suitable for installation of the Heartfelt device Pathway A: High risk patient with daily diuretics * Currently prescribed ≥40 mg/day of furosemide (or equivalent loop diuretic, eg. bumetanide or torsemide) for at least one month, AND * Any cardiorespiratory admission\*\* in the last 12 months (Includes outpatient IV diuretics, subcutaneous loop diuretics, or escalation to combination therapy with a loop diuretic and a thiazide or thiazide-like diuretic (eg: metolazone, bendroflumethiazide, indapamide etc). Pathway B: High risk patient without daily diuretics * Patients prescribed SGLT2 inhibitor (eg; dapagliflozin or empagliflozin) , AND * Patients prescribed oral furosemide ≥40mg/day but advised to take it only as needed AND either: a) at least two admissions\* caused or complicated by worsening heart failure in the previous 12 months, OR b) a measurement of plasma NT-proBNP exceeding 1,000 ng/L (pg/mL) in the previous 12 months Pathway C: Implanted Haemodynamic Monitoring Devices (minimum n=10 participants) * Uses an implantable device designed to monitor congestion (e.g. CardioMEMS, HeartLogic, or equivalent) * Enrichment criteria: Patients must also meet a minimum total score of 4 from the characteristics below. 1. NYHA class III and IV (score: 2) 2. ≥80 mg/day Furosemide or equivalent loop diuretic (score: 2) 3. \<3 Number of times the patient has weighed themselves in the last 2 weeks (score: 2) 4. Help for essential daily activities required (score: 2) 5. GRMT score \<5 (score: 2) 6. Use of a walking stick, walker or mobility scooter (score: 2) 7. \>2 Number of HF events in last 12 months (score: 2) 8. Aged over 75 (score: 1) 9. Health issues limiting daily activities (score: 1) 10. Help getting to medical appointment required (score: 1) 11. Problematic / not tolerated uptitration of medications: MRA (score: 1) SGLT2i (score: 1) Other (score: 1) 12. English as a second language (score: 1) 13. eGFR 20-45 (score: 1) 14. Patient unable to regularly attend appointments for any reason (score: 1) 15. \>3 Number of co-morbidities (score: 1) Exclusion Criteria: * Amputation of both feet * Bed-bound for more than 20h per 24h period * Bandages to lower limbs every day * Regular wheelchair user inside their home * No fixed abode * Participation in another interventional trial that may interfere with endpoints * Life expectancy \<6 months, in the opinion of the investigator * Inability to provide informed consent due to cognitive impairment * Language barriers that preclude understanding of trial procedures (unless translation resources are available in relevant language) * Inability to install the device (even with assistance) allowing at least 6 months of data capture by the end of the study. * Patients with severe aortic stenosis or awaiting a heart procedure or surgery * Patient with end stage renal disease (eGFR \<20) * Pregnancy or lack of contraceptive measures if of child-bearing potential