Affiliation: | 1. Mayo Clinic, Rochester, Minnesota;2. Cardiovascular Research Foundation, New York, New York;3. Medical City, Dallas, Texas;4. University of British Columbia and St. Paul''s Hospital, Vancouver, British Columbia, Canada;5. Washington Hospital Center, Washington, District of Columbia;6. Columbia University Medical Center and New York Presbyterian Hospital, New York, New York;g Cleveland Clinic Foundation, Cleveland, Ohio;h Emory University, Atlanta, Georgia |