1. Cardiology Division; Massachusetts General Hospital; Boston MA USA
2. Baim Institute for Clinical Research; Boston MA USA
3. Department of Mathematics and Statistics; Boston University; Boston MA USA
4. Cardiology Division; Radboud University Medical Center; Nijmegen The Netherlands
5. Cardiology Division; Maastricht University Medical Center; Maastricht The Netherlands
6. Cardiology Division; Brigham and Women's Hospital; Boston MA USA
7. Cardiology Division; VA Connecticut Healthcare System and Yale University; New Haven CT USA
8. Department of Biostatistics; Boston University; Boston MA USA