1 Centre for Cardiovascular Sciences, British Heart Foundation Centre of Research Excellence, Queen's Medical Research Institute, Edinburgh Royal Infirmary, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
2 Department of Medicine, Jagiellonian University, Collegium Medicum, Krakow, Poland.
3 Radcliffe Department of Medicine, British Heart Foundation Centre of Research Excellence, John Radcliffe Hospital, University of Oxford, Oxford, UK.