The trial is a multi-centre, prospective, randomised, unblended, controlled trial of intermittent PD with a single daily exchange of icodextrin plus best standard care versus best standard care for the treatment of severe HF and moderate CKD. A second exchange with glucose based solution may be given, should it be required in the investigator's/clinician's opinion. Investigators will randomise 130 participants for 32 weeks with randomisation stratified by participating centre. Participants will be recruited from specialist-led outpatient HF services in 6 NHS trusts and be managed by both cardiologists and nephrologists.