1. Department of Cardio-Thoracic Surgery, Maastricht University Medical Center , Maastricht , The Netherlands
2. Cardiovascular Research Institute Maastricht (CARIM), Maastricht University , Maastricht , The Netherlands
3. Department of Physiology, Maastricht University , Universiteitssingel 50, PO Box 616, 6200MD Maastricht , The Netherlands
4. Department of Cardiac Surgery, UZ Brussels , Brussels , Belgium
5. Department of Cardiology, Maastricht University Medical Center , Maastricht , The Netherlands
6. Department of Cardiac Surgery, Clinic for Cardiac Surgery, Heart Centre Leipzig , Leipzig , Germany