1. Department of Cardiothoracic Surgery, Aarhus University Hospital, Skejby, Aarhus, Denmark
2. Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus, Denmark
3. Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
4. Department of Cardiothoracic Surgery, Lund, Sweden
5. Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden
6. Department of Cardiology University Hospital, Lund, Sweden