1. Freeman Hospital, The Newcastle upon Tyne Hospitals NHS Foundation Trust , NE7 7DN , UK
2. Critical Care and Cardiology, Royal Brompton Hospital (Part of Guy’s and St Thomas’ NHS Foundation Trust) , Sydney Street, London, SW3 6NP , UK
3. National Heart & Lung Institute, Imperial College , Guy Scadding Building, Dovehouse St, London, SW3 6LY , UK
4. Department of Cardiology, Faculty of Medicine, School of Health Sciences, University of Ioannina and University Hospital of Ioannina , 45110 Ioannina , Greece