1. Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
2. Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, MA
3. National Heart, Lung, and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA
4. Cardiology and Preventive Medicine Sections, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
5. Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
6. Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, MA
7. Department of Epidemiology, Boston University School of Public Health, Boston, MA
8. Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA