2 MTRC, Anglia Ruskin School of Medicine, Chelmsford, Essex, UK.
3 Second Department of Cardiology, Attikon University Hospital, National and Kapodistrian University of Athens Medical School, Athens, Greece.
4 King's College Hospital NHS Foundation Trust, London, UK.
5 School of Cardiovascular and Metabolic Medicine and Sciences, British Heart Failure Centre of Excellence, King's College London, London, SE5 9NU, UK.