1. Department of Cardiothoracic Surgery, Erasmus University Medical Centre , Room Rg-633, P.O. Box 2040, 3000 CA Rotterdam , The Netherlands
2. Department of Cardiothoracic Surgery, Radboud University Medical Centre , Nijmegen , The Netherlands
3. Department of Cardiology, Radboud University Medical Centre , Nijmegen , The Netherlands
4. Department of Cardiothoracic Surgery, University Medical Centre Utrecht , Utrecht , The Netherlands
5. Department of Cardiology, Erasmus University Medical Centre , Rotterdam , The Netherlands