1 Essex Cardiothoracic Centre, MSE Trust, Basildon, Essex SS16 5NL, UK; Anglia Ruskin School of Medicine and MTRC, Anglia Ruskin University, Chelmsford, Essex, UK.
2 Department of Clinical Sciences Lund, Sections of Cardiology, Sweden.
3 Department of Clinical Sciences Lund, Sections of Anesthesiology and Intensive Care, Sweden.
4 King's College Hospital NHS Foundation Trust, London, UK; School of Cardiovascular and Metabolic Medicine and Sciences, British Heart Failure Centre of Excellence, King's College London, UK.
5 Essex Cardiothoracic Centre, MSE Trust, Basildon, Essex SS16 5NL, UK; Anglia Ruskin School of Medicine and MTRC, Anglia Ruskin University, Chelmsford, Essex, UK. Electronic address: thomas.keeble2@nhs.net.