1. Martini Hospital, Groningen, THE NETHERLANDS
2. Cardiovascular Research Institute Maastricht (CARIM), Maastricht, THE NETHERLANDS
3. University Medical Center Groningen, Groningen, THE NETHERLANDS
4. Medical Center Leeuwarden, Leeuwarden, THE NETHERLANDS
5. Zaans Medical Center, Zaandam, THE NETHERLANDS
6. Isala Hospital, Zwolle, THE NETHERLANDS
7. Canisius—Wilhelmina Hospital (CWZ), Nijmegen, THE NETHERLANDS
8. Spaarne Gasthuis, Haarlem, THE NETHERLANDS
9. Amsterdam University Medical Centre (AMC), Amsterdam, THE NETHERLANDS