1. Quebec Heart and Lung Institute, Laval University, Quebec City, Canada (L.A., M.B., J.R-C.).
2. University Hospital Salamanca, Spain (I.C-G., R.G-F.).
3. Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (L.N-F., T.R-G.).
4. Hospital de la Santa Creu i Sant Pau, Barcelona, Spain (D.A., V.A.).
5. Hospital Universitario Son Espases, Palma, Spain (V.P., M.A.).
6. University Heart Center Zürich, University Hospital of Zurich, Switzerland (F.N., R.G.).
7. San Raffaele Hospital, Milan, Italy (A.L., A.M.).
8. Montefiore Medical Center, New York (A.L.).
9. Fondazione Poliambulanza, Brescia, Italy (D.M.).