1. Department of Cardiovascular Surgery, Hospital Clínic de Barcelona, University of Barcelona , Barcelona, Spain
2. Cardiovascular Surgery Division, Mayo Clinic Rochester , Rochester, MN, USA
3. Cardiac Surgery Department, Pauls Stradiņš Clinical University Hospital , Riga, Latvia
4. Department of Cardiothoracic Surgery and The Robert WM Frater Cardiovascular Research Centre, University of the Free State , Bloemfontein, South Africa