1. University of Pennsylvania, Philadelphia, PA
2. Medical University of South Carolina, Charleston, SC
3. Aarhus University, Aarhus, Denmark
4. Rigshospitalet, Copenhagen, Denmark
5. Aarhus University Hospital, Aarhus, Denmark
6. Karolinska Institutet, Stockholm, Sweden
7. Turku University Hospital, Turku, Finland
8. Sussex Cardiac Centre, Brighton, United Kingdom
9. Western University, London, ON, Canada