1. Division of Cardiology, Deparment of Internal Medicine, Wake Forest University, Winston-Salem, NC 27157, USA
2. Division of Epidemiology, Human Genetics and Environmental Sciences, University of Texas Health Sciences Center at Houston, Houston, TX 77030, USA
3. Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN 55455, USA
4. Departments of Medicine and Epidemiology, University of Washington, Seattle, WA 98105, USA
5. Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 2187-0020, USA
6. Department of Radiology, Columbia College of Physicians and Surgeons, New York, NY 10032, USA