1 Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Vienna, Austria.
2 Sulpizio Cardiovascular Center, Division of Cardiovascular Medicine, University of California San Diego, La Jolla, CA, USA.
3 King's British Heart Foundation Centre, School of Cardiovascular and Metabolic Medicine & Sciences, King's College London, 125 Coldharbour Lane, London SE5 9NU, Greater London, UK.