1. Division of Cardiology, Department of Medicine, Cedars-Sinai Research Institute, Cedars-Sinai Medical Center, Pittsburgh, Pennsylvania
2. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
3. Division of Cardiology, Department of Medicine, University of Florida, Gainesville, Florida
4. Division of Cardiology, Department of Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania
5. Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
6. Division of Cardiology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
7. Rhode Island Hospital, Providence, Rhode Island
8. Division of Heart and Vascular Diseases, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland