1. Division of General Internal Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
2. Division of Preventive Cardiology, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.
3. Department of Internal Medicine. Mayo Clinic, Rochester, Minnesota.
4. Department of Health Science Research, Mayo Clinic, Rochester, Minnesota.
5. Division of Cardiology, Department of Medicine, Queen Elizabeth II Health Sciences Center, Dalhousie University, Halifax, Canada.